Increasing wet weather

Scattered showers and thunderstorms are expected across large portions of western Colorado on Sunday, possibly including the Stoner Mesa fire and the Derby fire sites.   Air quality health advisories will remain in effect for areas close to those two fires and smoke levels remain elevated Sunday morning.  However we are cautiously optimistic that there will be a general improvement in air quality over the next 24 hours due to less fire activity from cloud cover, and perhaps wetting rains from the shower and thunderstorm activity.

Geocolor satellite image of widespread cloud cover over western Colorado Sunday morning.  Image courtesy of Cooperative Institute for Research in the Atmosphere at Colorado State University

No major changes for the time being

 Air quality conditions Saturday morning look very similar to what they were 24 hours ago (see yesterday's blog post below).  Heavy smoke is mainly found in close vicinity to the Stoner Mesa fire in southwestern Colorado and the Derby fire in central Colorado.  Air quality health advisories will continue for these areas through at least Sunday morning.

There will be a scattering of showers and thunderstorms near the two fires Saturday afternoon, but wetting rains appear more likely on Sunday. We are hopeful this will continue the gradual improvement in air quality as we head into the early part of the workweek.

Relief on the way?

 Another day of localized heavy smoke near the Stoner Mesa fire and the Derby fire. Much like yesterday, the heaviest smoke will likely remain in close vicinity to the fires.  For Stoner Mesa, parts of western Eagle and eastern Garfield Counties remain in the advisory area. The Sweetwater Lake area along with Colorado River Road between Dotsero and Burns will receive heavy smoke during the overnight and early mornings, with improving air quality during the afternoons.  Yesterday afternoon we did see some downwind impacts in places like Basalt and Aspen.  That possibility exists again today, but with showers and thunderstorms possible near the fire there could be gusty, erratic winds that could send smoke in any direction. Regardless, we don't anticipate smoke to travel very far from the fire site today.

At the Stoner Mesa fire, there has been very heavy smoke along Highway 145 between Dolores and Rico.  The Stoner area has been especially hard hit, so if you are camping or reside in this area please take action to protect your health.  You can even create a clean air space in your RV by constructing a DIY air cleaner.

The forecast appears encouraging for western Colorado over the next few days as a surge of monsoonal moisture should help decrease fire activity and smoke production.  In the meantime, we'll continue to monitor the smoke and issue advisories if necessary. 

Smoky conditions will continue Thursday for parts of central and southwestern Colorado

 The Derby fire is located in central Colorado approximately 13 miles north of Dotsero and remains quite active Thursday morning. CDPHE issued an air quality health advisory yesterday for four counties due to smoke moving to the south and east of the fire. One concern was that smoke would be trapped within the narrow mountain valleys in this area, but fortunately many parts of the advisory area only have light to moderate smoke Thursday morning.  Therefore, the advisory for today will be smaller with the removal of Summit, Lake, and Pitkin Counties.  Eastern parts of Eagle County also look OK, but the advisory today will continue for western Eagle County with the addition of a small part of eastern Garfield County. Below is a map with areas most likely to receive periods of heavy smoke through Friday morning.

The area of concern for heavy smoke Thursday morning through Friday morning near the Derby fire.

 Heavy morning smoke can be expected in the vicinity of Sweetwater Lake in eastern Garfield County, along with locations on Colorado River Road between Dotsero and Burns. Meanwhile, the stretch of Interstate 70 between Dotsero and Eagle (including Gypsum) are also included in today's advisory.

A new data point has revealed that heavy smoke is still impacting parts of southeastern Dolores and northeastern Montezuma Counties in southwestern Colorado from the Stoner Mesa fire.  Campgrounds and residences along Highway 145 between Dolores and Rico, especially in the Stoner area, will experience heavy smoke Thursday morning with likely some improvement during the afternoon hours.  Smoke will likely return again to this area late Thursday night and early Friday morning.

The area of concern for heavy smoke Thursday morning through Friday morning near the Stoner Mesa fire.

Looking ahead, there is some promising news in the long-range forecast for the Western Slope.  An increase in monsoonal moisture is anticipated starting on Friday and continuing into the weekend.  This should help to decrease fire activity and smoke production somewhat, but we will also need to monitor for potential new fire starts from lightning strikes.

Air Quality Advisory issued downwind of the Derby wildfire

 The Derby fire has grown significantly over the past 24 hours and is producing very large amounts of smoke Wednesday afternoon.  The transport winds over the fire are not particularly strong, but they are pushing smoke to the south and east.  This has resulted in increased fine particulate (PM2.5) concentrations and worsening air quality across large swaths of Eagle, Summit, Pitkin, and Lake Counties.  An Air Quality Health Advisory for Wildfire Smoke has been issued for this area through at least 9am Thursday morning.   

The numerous communities along that long stretch of Interstate 70 between Silverthorne and Dotsero will be impacted by reduced visibility and periods of moderate to heavy smoke. Also expect increasing smoke Wednesday evening in places like Aspen and Leadville.  So please drive safely in areas where visibility is obscured. And as always, we remind you to please take action to protect your health. The valleys in this part of Colorado are notorious for trapping smoke, so this could very well be an issue through the Thursday morning commute.

GeoColor image of the Derby fire and heavy smoke located in northwestern Eagle County. Image courtesy of Cooperative Institute for Research in the Atmosphere at Colorado State University

Derby Fire burning in Eagle County

A new fire has sparked in northern Eagle County- the Derby Fire. 

Smoke from this fire is visible on satellite and is spreading south and east. Smoke may be visible Wednesday morning along the I-70 corridor, including Dotsero, Gypsum, Eagle, and Edwards. Throughout the day, there may be brief periods of moderate smoke. Particulate matter concentrations may begin to increase Wednesday afternoon, but will likely remain in the Moderate category.

No major public health impacts are expected at this time, and there is no Air Quality Health Advisory in effect. CDPHE is monitoring the situation and will issue an advisory if conditions change. Find the latest air quality information on PurpleAir or on CDPHE's monitoring website.

View of the Derby Fire on August 18. Image courtesy of InciWeb.

The Lee Fire, Stoner Mesa Fire, and Turner Gulch Fire are still burning in western Colorado. Locations near these fires may see periods of moderate smoke today. But unlike last week, widespread, heavy smoke is not expected from these fires today.

Areas of morning smoke near the fires on Sunday

 Air quality monitoring and satellite imagery reveal some smoke located in close vicinity to West Slope wildfires Sunday morning.  Smoke has drained overnight from the Stoner Mesa fire extending southwestward into Montezuma County with smoke being reported in Dolores, Cortez and Towaoc.  Fortunately, this smoke should decrease as progress through the morning and no advisory is necessary at this time.  If you do want to spend time outdoors in this part of Colorado, waiting until this afternoon would probably be the best choice for your personal health. The same holds true for those located close to the Crosho fire or Lee fire located in Rio Blanco County in northwestern Colorado.

The weather is steadily drying out across western Colorado so the wildfires may start getting active again Sunday afternoon.  We will keep you posted if any air quality advisories are necessary.

A hazy early morning at Cortez Municipal Airport.  Image courtesy of the Federal Aviation Administration

Air quality improves for Saturday

Today is the day- finally, no air quality health advisories are in effect!

The Lee Fire, Crosho Fire, and Stoner Mesa Fire are still burning. On Friday, western Colorado experienced rain and high relative humidity. This limited the fires' growth and resulted in less smoke from these fires. Today, Coloradans are waking up to cleaner air. 

We do not expect Particulate Matter concentrations to reach the Unhealthy for Sensitive Groups (orange) category today. There still may be a noticeable haze today. In areas near the fires, there may be periods of moderate smoke. If you are very sensitive to smoke, you can take steps to protect your health. But know that today will be an improvement from earlier this week.

Particulate matter concentrations are in the Good to Moderate range statewide.

PurpleAir Sensors are showing Good to Moderate air quality Saturday morning. Image courtesy of PurpleAir.

CDPHE is still monitoring these fires and will issue advisories as needed. 

Significant improvement in air quality for many areas

 Widespread cloud cover, higher relative humidity, and even a few showers and thunderstorms resulted in a decrease in fire activity yesterday on the Western Slope.  The result is lower smoke levels for most of Colorado Friday morning.  More good news -- moisture continues to surge into western Colorado.  This should moderate fire activity again for today and limit smoke production.

Friday morning satellite image of moisture surging into the Four Corners area. Image courtesy of Cooperative Institute for Research in the Atmosphere at Colorado State University

With less fire activity expected today, smoke impacts should be more localized.  We have decreased the size of both air quality health advisories in western Colorado.  Heavier smoke impacts should remain in close vicinity to the Lee fire, Crosho fire, and Stoner Mesa fire.  For the Lee and Crosho fires, expect heavier smoke to remain in rural areas of Rio Blanco county close to the fires, along with southern Routt County in the Phippsburg area.  This smoke will likely be heaviest during the early morning hours, so outdoor plans may be more appropriate during the afternoons.  It is a similar story on the Stoner Mesa fire where unhealthier smoke levels will mainly be confined to eastern Dolores and northern Montezuma Counties, including the communities of Rico and Dolores.

Looking ahead, the weather will likely gradually dry out again over the course of the weekend, so if you are in an area with improved air quality today you may want to take advantage of it.

Wildfire smoke remains in the forecast for many

 Most of Colorado is experiencing at least moderate levels of smoke Thursday morning.  The heaviest smoke can be found in close vicinity to wildfires in western parts of the state, while the Colorado River Valley between Gypsum and Vail is also seeing highly elevated levels of fine particulate matter.

Wildfire smoke producing moderate (yellow) to unhealthy for sensitive groups (orange) levels of fine particulate matter Thursday morning.  Map and data courtesy of the EPA's Fire and Smoke Map

Unfortunately Red Flag Warnings blanket the western half of Colorado on Thursday.  The primary threat will be dry thunderstorms which could initiate new fires and perhaps enhance current fires due to gusty winds.  CDPHE meteorologists will be closely monitoring for new wildfire starts throughout the day.

Counties shaded in pink are under a Red Flag Warning on Thursday.  Image courtesy of the National Weather Service GIS Viewer

The Air Quality Health Advisories that were in effect yesterday will be extended through at least Friday morning, but there will be some changes.  We do anticipate the Lee fire and the Crosho fire to remain active today and send smoke downwind to the northeast.  This will increase the potential for smoke in places like Steamboat Springs and Walden Thursday afternoon.  The highest smoke impacts will remain for areas along and north of Interstate 70 in northwestern and north-central Colorado.  Meanwhile, we do anticipate some gradual improvement for areas a bit further to the south and west, including Grand Junction, Delta, Montrose and Gunnison.  Those areas have been removed from today's advisory, but locals should still take it a little slower than usual as the recent exposure to smoke could have some lingering health impacts.

Meanwhile in southwestern Colorado, the Stoner Mesa fire continues to burn in eastern Dolores County.  This area is also under a Red Flag Warning and could see some growth today, especially if it is impacted by gusty outflow winds from dry thunderstorms.  One small piece of good news is that the transport winds are not particularly strong today in southwestern Colorado, so we are not expecting smoke to move very far away from the fire.  Therefore, air quality should improve somewhat in places like Telluride, Ouray and Silverton.  The flip side is that we are seeing increasing amounts of drainage smoke.  This is the smoke that flows downhill during the early morning hours and generally is at its worst right around the morning rush hour. Cortez and Durango have both seen an uptick in smoke over the past 24 hours.  Though these areas should see some improvement Thursday afternoon once the atmosphere heats up, smoke could very well return late Thursday night into early Friday morning.

Surface smoke at Cortez Municipal Airport Thursday morning. Image courtesy of the Federal Aviation Administration

Below is a map of Colorado showing active Air Quality Health Advisories.  With the rapidly changing atmospheric and wildfire conditions, we urge you to remain up-to-date on current advisories by visiting our website and signing up for email alerts.

Current Air Quality Health Advisories, by county.  Map from Colorado Department of Public Health and Environment, Air Pollution Control Division website

Increased fire activity and smoke possible today for parts of Colorado

 Unfortunately, it appears that the hot, dry, and increasingly windy weather could increase fire activity on Wednesday.  The biggest area of concern will be the large wildfires burning in Rio Blanco County.  These include the Lee fire and the Crosho fire.  A Red Flag Warning has been issued by the National Weather Service for this area, which could lead to explosive wildfire growth and enormous amounts of smoke.  We will be closely watching areas downwind (to the east) of these fires where smoke could quickly increase Wednesday afternoon and evening.  Several counties to the east of the fires have been added to the air quality health advisory currently in effect for this area.  Heads up today along Interstate 70 in Vail and Breckenridge, along with areas to the north including Kremmling, Fraser, and Granby.

Wednesday morning smoke spreading eastward from wildfires in Rio Blanco County. Image courtesy of Cooperative Institute for Research in the Atmosphere at Colorado State University 

Further south, areas of heavy smoke have been observed Wednesday morning in and around Grand Junction, Montrose, Delta, and Gunnison.  Although we are expecting gradually improving air quality conditions in this area Wednesday afternoon, the Turner Gulch fire in Mesa County is still producing smoke. Therefore, this area will remain within the air quality health advisory for the time being.

Even further south in southwestern Colorado, the Stoner Mesa fire remains active.  The weather conditions at this fire on Wednesday will not be quite as dry or windy as the fires to the north, which is good news.  However, heavy smoke will continue to be an issue for areas in close vicinity to the fire such as the communities of Rico and Dolores.  Some downwind impacts will also remain possible Wednesday afternoon and evening in Telluride, Silverton, Ouray, and Lake City, with the air quality health advisory remaining in effect for this area through at least Thursday morning.

Stoner Mesa fire on August 12, 2025.  Image courtesy of InciWeb

Smoke impacts continue on Tuesday, expected to be more localized

Several wildfires will continue to produce smoke on Tuesday, affecting air quality conditions for many areas of western Colorado. Wildfires in Rio Blanco and Mesa Counties will create impacts in northwestern and central Colorado, and fires in Dolores and Archuleta Counties will influence areas in southwestern portions of the state. The main difference in our expectations for today (versus yesterday) is that transport winds look to be lighter and less organized. This means that a lot of the smoke that is produced will remain in areas close to the fires. Air Quality Health Advisories for Wildfire Smoke will remain in place into Wednesday morning covering several counties, however please note that the footprint has changed somewhat.

Map of Colorado showing counties that are under advisories for smoke on Tuesday and Wednesday (shaded in grey). Map from colorado.gov/airquality .

One notable difference on Tuesday is the presence of smoke in the Grand Valley, including Grand Junction. The amount of smoke seen in this area has prompted the addition of Mesa County to the advisory area covered by the Lee fire and the Turner Gulch fire. Although smoke will remain within the valley through the morning hours, a gradual decrease has already been seen on Tuesday morning. This trend is expected to continue as atmospheric mixing increases. Improvement of conditions is expected in Grand Junction throughout the day on Tuesday.

A similar story is expected to unfold in southwestern Colorado near the Stoner Mesa fire in Dolores County. Smoke impacts will remain more localized than on Monday, with surface concentrations decreasing throughout the day in many areas. Drainage winds will still draw smoke toward lower terrain overnight, affecting eastern Dolores and northern Montezuma Counties.

We continue to watch all active incidents and will continue with updates here as things develop.

Smoke in many areas of western Colorado, with varying impacts and expectations

Wildfires and smoke will continue to be a part of many peoples' lives and conversations as we start the week, and rightfully so. There is much to address, so we will work from north to south, attempting to cover all aspects.

The largest fire(s) in Colorado, producing some of the greatest impacts include the Lee and Elk fires in Rio Blanco County. Combined, these fires cover around 130,000 acres and have limited containment as of Monday. Winds will transport smoke to areas to the south and southeast of these fires, creating smoke impacts in neighboring counties. Information on the extent of the greatest impacts can be found in the Air Quality Health Advisory for these fires.

Satellite image of heat detection of wildfires showing the location of fires throughout western Colorado. Image courtesy CIRA/CSU.

The second area of fire activity is in relation to the Turner Gulch fire in southern Mesa County. This fire continues to be active in interior portions of the fires' footprint, yet has not shown widespread smoke impacts for several days. Areas in the immediate vicinity of the fire will continue to see some smoke, and some areas may have moderate to heavy impacts at times. However from the information that is available to us including monitoring and coordination with fire managers, the severity and period of impacts from smoke do not support an Air quality Health Advisory for this fire at this time.

The third fire that is causing air quality impacts is the Stoner Mesa fire in eastern Dolores County. Smoke from this fire has largely been localized to areas near the fire, however as fire intensity and smoke production grows on Monday, additional areas may see smoke from this fire. Areas such as Cortez and Durango have seen intermittent periods of moderate to heavy smoke, however similar to  the Turner Gulch fire, the duration and severity of these episodes have not justified inclusion in advisories so far. As of this writing (Monday) the Air Quality Health Advisory for Wildfire Smoke related to this fire only coverers eastern Dolores County; though this may change with updated information.

The heat from all of these fires can be seen in the satellite image above, which shows infrared energy emitting from these incidents. What is not seen in the satellite image (or is very hard to discern) is the locations of two fires that are affecting areas of Archuleta County.

The Middle Mesa fire is in New Mexico, just south of the Colorado border, and the Oak fire is in Archuleta County to the northwest of Pagosa Springs. Both of these fires are certainly contributing to the presence of smoke in this region. However, as with other areas already motioned, the severity of impacts have not yet risen to levels that trigger an advisory.

CDPHE issues advisories when the AQI for particulate matter is expected to reach the Unhealthy for Sensitive Groups level over a 24 hour period. We are monitoring conditions and will issue more advisories as needed.

With all of this said, keeping the public informed of our expectations, and providing information so that you can make decisions on how best to protect your health is our ultimate goal. We will continue to monitor all of these situations as they evolve, and post additional updates as information becomes available.

Sunday smoke update

 The Lee Fire and Elk Fire are still burning in Rio Blanco County. An Air Quality Health Advisory remains in effect for a large area of central Colorado.

The Stoner Mesa Fire is still burning in Dolores County. An Air Quality Health Advisory is also in effect for eastern Dolores County today.

The advisory areas have slightly changed today. In central Colorado, Grand County has been added to the advisory area. In southwest Colorado, the advisory area only includes eastern Dolores County. Periods of moderate to heavy smoke are possible throughout both advisory areas on Sunday and Monday.

If you are sensitive to wildfire smoke, it's a good idea to take steps to protect your health today.

Smoke further south on Saturday

 It may be the weekend, but smoke isn't taking a day off.

The Lee Fire and Elk Fire continue to burn in Rio Blanco County. Smoke from these fires has moved south today, and Particulate Matter concentrations in central Colorado are higher. Cities and towns along the I-70 corridor, including Rifle, Eagle, and Vail, woke up to hazy, smoky skies this morning. Smoke is expected to stay south of Rio Blanco County today. In central Colorado, an Air Quality Health Advisory is in effect until 9 am Sunday morning. 

The Stoner Mesa Fire in Dolores County is also still burning today. Smoke from this fire has moved further east today, and a larger area is under the Air Quality Health Advisory.

If you are in a location under a Health Advisory, it's a good idea to take steps to protect your health today. Stay up-to-date with the latest air quality conditions on CDPHE's monitor map or Purple Air.

Also, a Red Flag Warning remains in effect for a large area of western Colorado, Utah, and Wyoming. CDPHE is monitoring the situation and will provide updates as needed.

Smoke continues in Colorado

Smoke is expected to continue today. Air Quality Health Advisories remain in effect for many counties in Colorado.

In northwestern Colorado, large wildfires are burning in Moffat and Rio Blanco Counties. Smoke from the Twelve Fire, Lee Fire, and Elk Fire is impacting much of northern Colorado.

In Dolores County, the Stoner Mesa Fire continues to burn. An Air Quality Health Advisory remains in effect for western Dolores County.

If you are sensitive to wildfire smoke, it is a good idea to take steps to protect your health. Visit CDPHE's monitoring website or Purple Air for real-time air quality data near you.

Additionally, a Red Flag Warning is in effect for several counties in western Colorado, Wyoming, and Utah. Any fires that spark could grow quickly today. We are monitoring the situation and will provide an update if necessary.

Ready for some good news? On the Front Range, air quality has improved from yesterday. On Thursday, there was an Action Day for Multiple Pollutants. Ozone and Particulate matter have improved slightly, and Good to Moderate air quality is expected for the Northern Front Range today.

Thursday smoke update

Smoke will continue for much of Colorado today.

In Moffat and Rio Blanco Counties, the Twelve Fire, Lee Fire, and Elk Fire are burning.

Smoke from these fires has moved east and is impacting a large area of northern Colorado. An Air Quality Health Advisory is in effect for northern Colorado. As of this morning, four counties were removed from the advisory area (Garfield, Eagle, Gilpin, and Clear Creek.) Smoke will remain further north today.

Smoke is visible from the Meeker Airport (facing southwest.) Image courtesy of FAA Weathercams.

On the Front Range, an Action Day for Multiple Pollutants is in effect. Both Particulate Matter (from smoke) and ozone are expected to be high today in Fort Collins, Greeley, Boulder, and the Denver Metro area.

In Dolores County, the Stoner Mesa Fire is still burning. An Air Quality Health Advisory is in effect for eastern Dolores County today.

Additionally, a Red Flag Warning is in effect for several counties in western Colorado, Wyoming, and Utah. Any fires that spark could grow quickly today. We are monitoring the situation, and will provide an update if necessary.

If you are sensitive to wildfire smoke, it is a good idea to take steps to protect your health. Visit CDPHE's monitoring website or Purple Air for real-time air quality data near you.

Smoke further east on Wednesday

On Wednesday, more Coloradans will be breathing in smoke. Let's break it down from north to south.

The Lee Fire and the Elk Fire are burning in Rio Blanco County. Smoke from these fires has moved east, reaching as far as the Northern Front Range. Moderate to heavy smoke is expected from Rio Blanco County and eastward to Weld County. An Air Quality Health Advisory is in effect. 

Satellite image of Colorado shows areas of smoke (gray, circled in red.) Image courtesy of RAMMB CIRA Slider.

The Turner Gulch Fire is still producing smoke, but not enough to trigger an advisory. Purple Air sensors in southern Mesa County are showing moderate levels of smoke. We will issue an advisory if conditions worsen. 

The Stoner Mesa Fire in Dolores County is producing moderate to heavy smoke. An Air Quality Health Advisory is in effect for eastern Dolores County today. On Wednesday, some smoke has moved south into La Plata County, particularly Durango. However, smoke isn't heavy enough to trigger an advisory. If smoke becomes heavier, we will expand the advisory area to include neighboring counties.

In addition to all of this activity within Colorado, several fires are still burning in other upwind states, and the transport of smoke into Colorado may also contribute to the ambient smoky conditions across large areas of Colorado.

If you are sensitive to smoke, it's a good idea to take steps to protect your health. Visit CDPHE's monitoring website or PurpleAir for the most up-to-date information on air quality conditions.

Continued smoke on tap for Tuesday

 The smoke continues today in western Colorado. Air Quailty Health Advisories are in effect for several counties on the Western Slope. We'll discuss the details in two parts.

First, fires burning in Rio Blanco and Garfield Counties are causing air quality impacts for a large portion of western Colorado. The heaviest impacts will be in locations near the Grease/ Lee Fires, Elk Fire, and Coulter Creek Fire. 

 Smoke is expected to move further east today, so this advisory was updated to include Grand and Jackson Counties.

Webcam view from the Meeker Airport shows heavy smoke on the horizon. Photo courtesy of FAA Weathercams.

Second, the Sharp Canyon Fire burning in western Dolores County is expected to cause periods of moderate to heavy smoke today. The heaviest smoke is expected in locations close to the fire. 

A Red Flag Warning remains in effect for a large area of western Colorado. Hot, dry, and windy weather means that conditions are good for fire growth. Any new or existing fires could grow quickly today. We are monitoring the situation and will provide updates as necessary.

If you are sensitive to wildfire smoke, it's a good idea to take steps to protect your health. 

Wildfires in western Colorado could intensify today

Smoke from several wildfires is impacting western Colorado today.

The Grease Fire, Lee Fire, Elk Fire, and Coulter Creek Fire are burning in northwest Colorado. An Air Quality Health Advisory for Wildfire Smoke is in effect until 9 am Tuesday for eastern parts of Rio Blanco and Garfield Counties, along with the entirety of Routt and Eagle Counties. Areas close to the fires will obviously see periods of moderate to heavy smoke today, including the Meeker area.  

Webcam view from Eagle County Airport facing southwest. Smoke is visible on the horizon. Image courtesy of FAA Weathercams.

Additionally, dry and windy weather is on tap for today. A Red Flag Warning is in effect for a large portion of western Colorado, as well as parts of Wyoming and Utah. This means that any new or existing fires could grow quickly today and produce large amounts of smoke. We will be closely watching areas well downwind of the fires today, including Steamboat Springs which could see an increase in smoke later this afternoon and into this evening. 

If you are particularly sensitive to smoke, it's a good idea to take steps to protect your health. 

New fires spark in western Colorado, fires in other states still active

Several wildfires are creating air quality concerns in areas of western Colorado. The Grease fire and the Elk fire are located in central and eastern Rio Blanco County, and the Coulter Creek fire is located in southeastern Garfield County. These fires will produce areas of moderate to heavy smoke on Sunday evening and Monday morning, particularly in areas of low lying terrain in the immediate vicinity of the fires.

Map of fire locations in western Colorado on August 3rd, 2025. Map courtesy of fire.airnow.gov.

An Air Quality Health Advisory for Wildfire Smoke has been issued for areas near these fires through at least Monday morning. Folks in these areas should take steps to avoid exposure to smoke and limit health impacts. 

Fires in other states continue to produce smoke, resulting in light to moderate concentrations of fine particulates in other areas of the State. While conditions across the western slope and 4-Corners regions of Colorado do not warrant advisories at this time, anyone in these areas should also remain aware of air quality conditions due to the presence of smoke.

We will continue to provide updated information on smoke impacts, including additional advisories if necessary.

Wildfires still burning, moderate smoke impacts expected through the weekend

Many areas of Colorado have noticed the presence of wildfire smoke this week, with hazy skies and Moderate particulate concentrations. Unfortunately, this is expected to continue through the coming weekend. Fire activity in Colorado has remained moderate, with the primary influence being from the Turner Gulch Fire in southern Mesa County. However the Monroe Canyon fire in central Utah and the Dragon Bravo fire in Arizona have continued to display active fire behavior, and are expected to remain this way during the coming weekend. 

Map from fire.airnow.gov shows the location of several fires in the western U.S., with smoke plumes extending over Colorado. Air quality monitors show Moderate (yellow) smoke impacts.

Upper level transport winds are expected to shift, becoming more west-to-east in orientation throughout the weekend. This will bring smoke from fires more directly into Colorado, likely continuing the Moderate impacts that have been seen this week.

Resulting impacts will depend on just how active the fires are, the direction and altitude of smoke transport, and how deep atmospheric mixing is in areas where the plumes traverse. As always we will keep a close watch on air quality conditions and will send messaging and alerts (if needed) to keep you informed. We also encourage folks to take note of conditions in your location, and take the steps most appropriate for your situation to minimize effects of smoke exposure.

Smoke set to increase across Colorado over the next 24 hours

 If you are sneezing a bit more than normal today or have a scratchy throat, wildfire smoke is likely to blame.  We are not seeing overly heavy smoke anywhere across the state Thursday morning, but there are plenty of areas measuring moderate levels of particle pollution.

EPA's Fire and Smoke Map shows moderate (yellow) levels of fine particulates across large parts of Colorado Thursday morning

Unfortunately it appears that smoke levels will increase over the next 24 hours.  The main culprits of the current particle pollution are the Dragon Bravo fire in northern Arizona and the Monroe Canyon fire in central Utah.  Combined, these two fires have consumed nearly 150,000 acres under record-breaking dry conditions. 

Starting today, the transport winds at these two fires will begin to shift to a more westerly direction.  The consequence of this will be an increase in smoke moving towards Colorado Thursday afternoon and into Friday.  At this point, it is difficult to know exactly where the heaviest smoke in Colorado will be on Friday. However it does appear that the entire state will be impacted to some degree, so please prepare to take extra actions to protect your health.  We will certainly keep you updated on the very latest developments, including issuing air quality health advisories if needed.

Smoke versus storms

There were definitely some concerns for heavy smoke across northwestern Colorado yesterday.  Fortunately, fine particulate concentrations across the region have remained at moderate levels.  Consequently, the Air Quality Health Advisory for Wildfire Smoke will be allowed to expire at 9am Wednesday.

No doubt there is still plenty of smoke high up in the atmosphere over western Colorado.  However, we also anticipate a surge in moisture across the region today. There should be enough turbulence in the atmosphere along with shower and thunderstorm activity to prevent smoke from getting too heavy.  So if you reside in Grand Junction, Steamboat Springs, Aspen, Telluride, or nearly anywhere else west of the Continental Divide, expect moderate levels of "nuisance" smoke today.  If you are especially sensitive to wood smoke, please continue to take action to protect your health.

Smoke aloft in the atmosphere over the Four Corners region on Wednesday morning.  Image courtesy of Cooperative Institute for Research in the Atmosphere

Smoke expected to increase in northwestern Colorado on Tuesday

Smoke from wildfires in other states has reached the northwestern corner of Colorado on Tuesday morning. Only moderate impacts have been seen as of this writing (Tuesday morning), however as daytime mixing of the atmosphere increases, we expect smoke that is aloft to be drawn downward and increase surface concentrations within the area covered in the Air Quality Health Advisory; issued for Moffat and Rio Blanco Counties.

A map from fire.airnow.gov shows the location of the smoke plume (shaded in grey) over air quality monitors in Colorado and Utah. Monitors in Colorado show Moderate air quality while the monitors in Utah show values in the Moderate to Unhealthy for Sensitive Groups AQI range. Map is from approximately 10:30 am MDT, July 29, 2025.

Folks in the northwest corner of Colorado are encouraged to remain alert to changing conditions and increasing smoke concentrations on Tuesday and into Wednesday. Take appropriate steps to avoid exposure and protect your health in this area.

Smoke returns to the Front Range

 A hazy, smoky sky over the Front Range region Tuesday morning. The vast majority of this smoke originated out-of-state in Utah and Arizona.  Fortunately for folks in Denver, Boulder, Ft. Collins, Greeley, and elsewhere along the Front Range, fine particulates are at moderate levels and shouldn't increase much more from where they currently are.  In fact, as the atmosphere heats up we should see smoke levels decrease late Tuesday morning and continuing through Tuesday afternoon.  In the meantime, you may want take it a little easier than usual Tuesday morning until the air quality improves.

Denver webcam at 6:34 am on Tuesday

 

Mesa County smoke advisory expires this morning

 As containment increases and available fuels to burn decrease on the Turner Gulch fire, air quality continues to improve across the region.  Therefore, the Air Quality Health Advisory for Wildfire Smoke will be allowed to expire at 9am this morning.  That being said, occasional periods of moderate to heavy smoke are expected to continue in places like Gateway and along Highway 141 surrounding the fire.  This heavier smoke should be brief and mainly occur during the early morning hours.  So if you do want to spend some time outdoors in this part of Colorado over the next few days, perhaps wait until after 10am and the smoke should clear out nicely.

The story is similar for the Rim Road and Elkhorn fires in La Plata County.  Outdoor activities are better suited during the late mornings and afternoons, if possible.  The heavier morning smoke in La Plata County will mainly be confined to locations along Highway 550 between Durango and Hermosa, and on County Road 318 in the vicinity of Los Pinos Fire Station 3.

Smoke advisory in Mesa County shrinks on Sunday

 Some good news in the Grand Valley this morning as air quality has improved quite a bit.  However, we are still seeing some pretty heavy smoke in close vicinity to the Turner Gulch fire. With a Red Flag Warning in effect today for Mesa County, the Turner Gulch fire will likely remain active in spots and bring another round of moderate to heavy smoke tonight and tomorrow for Gateway and other locations surrounding the fire on Highway 141.  With less of a threat for heavier smoke in other parts of Mesa County, the Air Quality Health Advisory for Wildfire Smoke will be in effect for only southern parts of Mesa County through Monday morning.

Meanwhile, there were two new wildfire starts yesterday in La Plata County.  The Elkhorn fire is located in northern La Plata County just east of Highway 550 about 15 miles north of Durango.  This fire is producing some moderate to locally heavy smoke around Hermosa and southward into the Durango area.  Fortunately the smoke should decrease by late Sunday morning as the atmosphere heats up.  Meanwhile, the Rim Road fire is located in southern La Plata County on the Southern Ute Reservation.  County Road 318 to the north of the fire and in the vicinity of Los Pinos Fire Station 3 could be impacted with smoke Sunday morning.  But much like the Elkhorn fire, smoke should decrease throughout the area with the heating of the day.

The good news with these two wildfires in La Plata County is that it should not be quite as windy as yesterday which decreases the threat for explosive fire development.  However, we will continue to monitor both of these fires for smoke production on Sunday and will issue an advisory if needed.

GeoColor satellite image of La Plata County wildfires on Saturday afternoon.  Image courtesy of Cooperative Institute for Research in the Atmosphere.

Getting hotter and drier

 Western Colorado will continue to see periods of hazy, smoky weather for the next few days. Currently, two fires are producing most of the smoke.  One of those is in Colorado, the other in Arizona. The Turner Gulch fire in Mesa County is not as active as it was last week due to recently favorable weather and some great work done by fire crews. However, there are still parts of the fire that are inaccessible for firefighters and could produce smoke as the weather continues to heat up and dry out.

Meanwhile the Dragon Bravo fire on the northern rim of the Grand Canyon in northern Arizona continues be very active and produce enormous amounts of smoke. That smoke is occasionally impacting Colorado, mostly western portions of the state.  The highest risk for more of this transported smoke over the next few days will be from west-central Colorado (around Grand Junction), northward into far northwestern Colorado.

Friday morning satellite image shows widespread smoke across northern Arizona, eastern Utah, and western Colorado.  Image courtesy of Cooperative Institute for Research in the Atmosphere.

All that being said, the highest risk for heavy smoke over the next 24 hours will be in Mesa County.  This is especially true for locations in close vicinity to the Turner Gulch fire.  Please take action to protect your health in Gateway, and also for those that reside along Highway 141 to the east of Gateway.  For other locations in Mesa County, including the Grand Valley, smoke concentrations are at moderate levels Friday morning.  However, smoke could increase beginning Friday afternoon depending on wildfire activity both locally and out-of-state.  The air quality health advisory for wildfire smoke has been extended for Mesa County through Saturday morning.  With the slight decrease in smoke concentrations in Grand Junction, taking advantage of the better air quality Friday morning might be a good idea.  But do keep in mind that fine particulate levels have been elevated for several days now and do have a cumulative impact on your health, so you may still want to limit heavy exertion for the time being.

Ongoing smoke impacts in Mesa County, western Colorado

 An increase in fire behavior and smoke production on Wednesday, mainly from from the Turner Gulch Fire in Mesa County and the Dragon Bravo Fire near the Grand Canyon in Arizona, has once again degraded air quality in areas of western and southwestern Colorado. The greatest impacts were seen in areas where the influence of both of these incidents were felt, and led to the reissuance of the Air Quality Health Advisory for Wildfire Smoke in Mesa County.

Map of fire locations and air quality monitors showing smoke impacts in western Colorado at approximately 9:30 am MDT on Thursday, July 24, 2025. Map courtesy of fire.airnow.gov.

Other locations throughout the 4-Corners region also saw an uptick in PM2.5 concentrations on Wednesday afternoon, and will likely contend with haze and Moderate air quality on Thursday and Friday. Smoke may linger in areas where it has infiltrated already, and additional smoke may arrive, depending on transport winds and fire activity on Thursday. Daytime mixing of the atmosphere will play a role on how quickly smoke may dissipate, and also how much smoke reaches the surface as the daily cycle of production and transport continues.

It appears that as upper level winds change direction as we move toward the weekend, the areas seeing smoke may shift. It is possible that the light to moderate impacts that are currently seen to the south of Mesa County, may move toward counties to the north and east of the Advisory area.

We will continue to watch these trends and will provide updates on smoke concentrations and our expectations as they become more clearly defined. We encourage everyone in western Colorado to remain aware of changing conditions and take health precautions as appropriate.

Heavy smoke moving into the Grand Valley and other parts of Mesa County

 Mesa County is now under an Air Quality Health Advisory for Wildfire Smoke through early Thursday morning.  Heavy smoke transported from the Dragon Bravo wildfire in northern Arizona along with a flare up in fire activity from local wildfires have made fine particulate levels spike all across Mesa County.  Closing the windows before going to bed tonight is a good idea in the Grand Junction area as smoke is not likely to decrease much during the overnight hours.

For additional information on how to protect your health from wildfire smoke, please visit the CDPHE Wildfire and smoke and health webpage.

Webcam image from Grand Junction Regional Airport shows heavy smoke Thursday evening.  Webcam image courtesy of the Federal Aviation Administration