Special Air Quality Statement
Widespread wildfire smoke will impact all of eastern Colorado along with the Grand Valley in western Colorado with elevated levels of both particle pollution and ozone.

Click here for advisory details.

Front Range
Action Day for Multiple Pollutants
Until at least 4 p.m. 07/25/2024

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The Colorado Department of Public Health and Environment and the Regional Air Quality Council have issued an ACTION DAY ALERT at 4 p.m. on Wednesday, July 24, 2024 for the Front Range Urban Corridor from Douglas County north to Larimer and Weld counties, including the Denver-Boulder area, Fort Collins and Greeley.

Heavy wildfire smoke will result in elevated levels of particle pollution and ozone through at least Thursday afternoon.

This Multiple Pollutants Action Day Alert will remain in effect until at least 4 p.m. Thursday, July 25, 2024.

For statewide conditions, forecasts and advisories, visit:

The highest Ozone related AQI at 9 o'clock PM Mountain Standard Time on July 24, 2024, is 166 which indicates Unhealthy ozone air quality. It was recorded by the RFN ambient ozone monitor. Greater likelihood of respiratory symptoms and breathing difficulty in active children and adults and people with lung disease, such as asthma; possible respiratory effects in general population. Active children and adults, and people with lung disease, such as asthma, should avoid prolonged or heavy outdoor exertion; everyone else, especially children, should reduce prolonged or heavy outdoor exertion.

The highest Particulate Matter (PM2.5) related AQI at 9 o'clock PM Mountain Standard Time on July 24, 2024, is 96 which indicates Moderate Particulate Matter (PM2.5) air quality. It was recorded by the ADB ambient monitor. Respiratory symptoms possible in unusually sensitive individuals, possible aggravation of heart or lung disease in people with cardiopulmonary disease and older adults. Unusually sensitive people should consider reducing prolonged or heavy exertion.

Summer Ozone Program
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Ground-level ozone is an air pollution problem that impacts the health of all Coloradans. Exposure can cause acute respiratory problems and trigger asthma attacks. During Ozone Action Alerts, avoid rigorous outdoor activity during the heat of the day. Prolonged exposure can cause long-lasting damage to your lungs.

You CAN make a difference by doing your part to improve air quality along Denver's Front Range. Even during periods of wildfire smoke, reducing your personal emissions can help decrease ozone production. Combining or skipping just two car trips a week has a positive impact on our air quality. Find other easy solutions that fit your lifestyle from Simple Steps. Better Air. (, a program of the Regional Air Quality Council.

Additional Information
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WHAT IS AN ACTION DAY?: An Action Day for fine particulate matter, carbon monoxide, ozone or other pollutants indicates that either current air quality is unhealthy or conditions are expected to worsen later in the day or on the next day. Action Days for air pollutants generally indicate that air quality will be in either the Unhealthy or Unhealthy-for-Sensitive-Groups categories according to the Air Quality Index. Action Days always convey overarching public health recommendations, and, according to season, trigger a variety of mandatory and voluntary pollution prevention measures. For example, during the summer open burning is prohibited when an Action Day for ozone and/or fine particulates is in effect. During the winter, residential burning restrictions are in effect when an Action Day for Visibility is in effect.

For a detailed description of both the AIR QUALITY INDEX and the VISIBILITY STANDARD INDEX please visit

For those with permits for open burning, that is the burning of waste materials or vegetation outside, check the following webpage to find out if open burning is allowed today. Keep in mind that open burning is prohibited when an Action Day is in effect:




AIR QUALITY NOTIFICATIONS: automated e-mail alerts) forecasts via automated e-mails from the EPA)