Elevated levels of smoke linger in areas near prescribed burns in southwestern Colorado

PurpleAir particulate monitors show that localized areas of smoke have continued to linger during overnight and early morning hours, due to prescribed fire activity that took place this week.

Screenshot from PurpleAir showing elevated levels of smoke in localized areas near Pagosa Springs, CO on Saturday morning. Raw PM2.5 data are corrected with US EPA conversion factor, using 1 hour timeseries, valid at 8:21 am on September 20, 2025.

Over the last several days, we have seen higher particulate numbers early in the day, with concentrations decreasing during the afternoon and evening as daytime mixing of the atmosphere and smoke dispersion take place. This pattern may continue until fuels have stopped smoldering. Similar smoke behavior may also be observed in other areas where prescribed burning has recently been performed.

We urge anyone in areas that are affected by smoke, especially those who are sensitive to particulate pollution, to remain aware of conditions and protect your health through whichever actions are most appropriate for you.