Smoky Denver rush hour

 As stated earlier, smoke from Nebraska wildfires has traversed across northeastern Colorado and arrived to the Denver metro area.  Fine particulate levels have spiked and visibility has degraded considerably. Fortunately, Denver and surrounding areas will see slow and gradual improvement through this evening. In the meantime, remaining indoors with the doors and windows closed is a good idea. While outside, slow it down a bit.  By later this evening, air quality is expected to improve noticeably.

Denver skyline webcam image Thursday afternoon (https://www.colorado.gov/airquality/live_image.aspx)

Updated expectations for smoke from the 24 Fire

Smoke impacts due to the 24 Fire, located on Fort Carson in south-central Colorado, will continue to be highly variable on Thursday and into Friday. Winds on Thursday have come mainly from the west. Winds are expected to remain breezy and gusty on Thursday afternoon and into the overnight period, however the direction will change as a cooler air mass moves in from the east. This has several implications for fire behavior and smoke impacts.

First, fire behavior may increase once again on Thursday, as was seen on Wednesday, during the warm and dry afternoon. This could increase smoke production, but may also will help with dispersion as atmospheric lift moves much of the smoke vertically away from the surface, and winds help to dissipate concentrations. The west-to-east transport will also limit impacts from smoke in areas of Fremont County, such as Penrose, Florence, and Cañon City.

The second change that we anticipate is a shift in the wind direction this evening, with winds switching to come from the east. This will move smoke in the opposite direction, and toward the above mentioned communities. As the winds shift, the air will cool as the sun goes down, and as cooler air is transported into the region. This will decrease lift in the atmosphere, and smoke may stay closer to ground level. This may create periods of smoke and haze, particularly in areas closest to the fire. Though the shift in wind direction may increase smoke in neighboring communities, breezy and gusty conditions will help to limit overall smoke concentrations.

Map showing the location of the 24 Fire near Cañon City, Colorado, with arrows indicating expected wind directions on Thursday, and Thursday night/Friday morning. Map image from WatchDuty App, 24 Fire information

The third change that is expected is an increase in relative humidity and chances for precipitation. The cool, moist airmass that is incoming will assist in decreasing fire behavior and smoke production. Higher humidity values will remain in the area, and as winds decrease a bit on Friday also, fire behavior is expected to be dampened. 

The take-away message from all of this is: changes are coming, so folks in areas near the 24 Fire should remain prepared to protect their health during any smoke episodes that may be experienced, but also know that these periods of impact are expected to be relatively short lived.

As of this writing (3 pm on 3/26/26) an Air Quality Health Advisory is not anticipated. CDPHE forecasters are watching as all of this unfolds, and will respond with messaging and alerts if they become necessary. As always, our goal is to communicate our expectations so that folks can make informed decisions on what is the right action to take, and when.

Smoke arrives in northeast Colorado, moving towards Denver

Smoke from Nebraska has moved into northeast Colorado. 

Smoke, in gray, is visible on satellite imagery. Image courtesy of RAMMB Cira Slider.

The Ashby Fire and the Minor Fire are burning in Nebraska. Smoke from these fires pushed into northeast Colorado on Thursday. Particulate matter concentrations are elevated for some locations in northeast Colorado, including Fort Morgan, Sterling, and Julesburg. 

Smoke is continuing to move southwest towards the Denver Metro area on Thursday afternoon. Some locations may notice a brief increase in particulate matter, but we do not expect prolonged periods of heavy smoke. 

No major public health impacts are expected at this time, but folks who are particularly sensitive to smoke may want to take steps to protect their health.

24 wildfire intensifying once again

 Hot, dry and windy conditions are once again increasing fire activity at the 24 wildfire located on Ft. Carson army base.  A large smoke plume has developed and is spreading to the north and east of the fire's location near the intersection of the El Paso, Pueblo, and Fremont county lines.  Fortunately, there is quite a bit of lift in the atmosphere that is keeping most of the smoke high up in the sky, though a few brief periods of smoke could move down to the surface near Fountain and southern parts of the Colorado Springs area.  

Some changes will likely arrive after the sun sets.  As atmospheric mixing decreases with cooler temperatures, smoke will start to hug the surface of the earth and potentially impact nearby communities.  We also anticipate the wind to shift which could send smoke in various directions. One direction it could move is to the south and southwest which could impact parts of Fremont County, including Cañon City, Florence and Penrose. This is most likely to occur at some point between 8pm and midnight Wednesday evening. Fortunately, any smoke that infiltrates these areas should be relatively brief (perhaps an hour or two), so significant health impacts are not anticipated at this time. However, it is always a good idea to take steps to protect your health when smoke is present in your neighborhood, including remaining indoors with the doors and windows closed until the smoke clears.

A cold front will be arriving Thursday night which could bring some more impactful changes to the air quality in Fremont County. A wind shift may push smoke into those same Fremont County locations discussed above for several hours Thursday night. Wet weather likely arrives Friday morning which would clear out the smoke and improve the air quality. We will monitor the situation closely and issue an advisory for Thursday night, if necessary.

View of the 24 wildfire from Fremont County Airport to the east of Cañon City (weathercams.faa.gov)

Update on 24 Fire in Fremont, El Paso, Pueblo Counties

The 24 Fire continues to burn near the Fremont/El Paso/Pueblo County intersection. The fire is currently at 7,404 acres with 24% containment. Portions of the fire remain active at times, producing smoke that may cause intermittent impacts in areas near the fire. Good atmospheric mixing and ventilation will help to lift and disperse smoke during daytime hours. However, warm and dry conditions are also expected, with a Red Flag Warning in place in areas near the fire. Breezy and gusty winds may be present on Wednesday and Thursday, and may increase fire behavior and smoke production. Additionally, periods of moderate to heavy smoke may be encountered during the overnight hours in locations adjacent to the most active portions of the fire.

Folks in areas near this incident are encouraged to take precautionary preparations to limit impacts from smoke, if conditions worsen quickly.

Over the last several days, periodic impacts from moderate to heavy smoke have been observed, but overall have not met conditions that warrant the issuance of a widespread or long-lasting Air Quality Health Advisory. CDPHE meteorologists continue to watch this incident closely, and will respond with advisories and alerts if necessary.

Wildfire on Ft. Carson remains active

 The 24 wildfire continues to actively burn on the Ft. Carson US Army post located near the intersection of the El Paso, Fremont, and Pueblo County lines.  It is now approaching 2000 acres in size with the recent, hot, dry and windy conditions.  

The good news is that the majority of the smoke has been lofting well into the sky during the afternoons and evenings for the past several days. Additionally, overnight smoke (which is generally the heaviest and creates the biggest health concerns) has remained away from the local communities.

One thing we are watching closely is the anticipated wind shift that will be arriving on Sunday.  This could push smoke into new directions, however it still appears that most of the nearby towns will be spared from the worst of the smoke impacts.  Despite this, there remains the possibility for brief periods of heavy smoke in communities to the south of the fire such as Penrose and Florence.  Even areas a bit further from the fire, including Pueblo and Cañon City, could see some smoke from time to time.  

Although an advisory is not anticipated at this time, residents in the area can get prepared to protect their health from wildfire smoke by visiting CDPHE's Wildfire smoke and health webpage. It could very well be a long and impactful wildfire season in Colorado, so being prepared now could certainly come in handy later this spring and summer.

Heat signature of the 24 wildfire from Band 7 shortwave satellite imagery on Saturday evening.

Smoke visible from Fremont County Fire

The 24 Fire in Fremont County sparked on Wednesday, March 18. A new plume of smoke appeared Thursday afternoon, pushing southeast. Hazy skies are likely this afternoon, particularly in Pueblo County. Residents in northeastern Fremont and southwestern El Paso counties also may notice haze.

A plume of smoke is visible on satellite imagery. Image courtesy of RAMMB Cira Slider.

Currently, atmospheric mixing is good, allowing smoke to mix vertically into the atmosphere, rather than sinking to the surface. Because of this, no major public health impacts are expected at this time. CDPHE will continue to monitor the situation and issue an Air Quality Health Advisory if necessary. 

Additionally, if you are located near the fire, you may consider taking steps to protect your health. 

For real-time air quality conditions near you, check Colorado's Monitoring Network or your nearest PurpleAir Sensor.

Lingering smoke in southeastern Colorado

 Although many parts of eastern Colorado have seen air quality improvement over the past several hours, some areas continue to deal with lingering smoke from wildfires in Nebraska.  The atmosphere has been a bit more stubborn in southeastern Colorado, particularly along the Arkansas River Valley from Pueblo eastward through La Junta to Lamar.  Therefore, the Air Quality Health Advisory for Wildfire Smoke has been extended through 9am Saturday morning.  Continue to limit activities that require physical exertion in this part of Colorado, and also reduce your time outdoors if possible.  The smoke should gradually decrease as we head into the start of the weekend.

A hazy sky over Kit Carson County Airport in Burlington (weathercams.faa.gov)

Friday morning surprise smoke across eastern Colorado

 Smoke from a couple of large wildfires in Nebraska has spread into eastern Colorado on easterly winds.  High levels of fine particulates have been reported Friday morning along the Platte River Valley from Julesburg westward into Sterling, Ft. Morgan, Greeley, and even parts of Ft. Collins along the foothills.  Smoke has also pushed into the east-central and southeastern plains. with smoke concentrating along the Arkansas River Valley from Lamar westward to La Junta and Rocky Ford.

The good news regarding air quality is that the smoke should rapidly dissipate during the morning hours across northeastern Colorado as gusty westerly winds develop.  These winds will improve atmospheric mixing and smoke should decrease quickly.  Smoke may linger a bit longer for areas further south, as it may not be until this afternoon until we see improvement along the Arkansas River Valley.  Due to the high levels of particle pollution with this smoke, an Air Quality Health Advisory for Wildfire Smoke has been issued.

Be sure to protect your health while smoke is present in your neighborhood.  Remaining indoors and avoiding physical exertion are a good start.  You can find more way to protect your health at CDPHE's Wildfire smoke and health webpage.

Heavy smoke Friday morning at Ft. Morgan Municipal Airport (weathercams.faa.gov)

Prescribed Burning Operations Planned at the Rocky Mountain Arsenal

Several prescribed burns are planned over the coming days and weeks at the Rocky Mountain Arsenal. Operations are intended to begin as early as Thursday March 5th. Smoke from prescribed burns may be visible from the Denver Metro area, especially in northern Denver and near the Rocky Mountain Arsenal.

For additional information on burning operations, please refer to the Prescribed Fire Map using the tab above. Also, you can find information about how smoke may affect your health on the CDPHE webpage: Wood smoke and your health.