Worst air pollution Boulder, today and tomorrow
Today (9 August): Air quality in Boulder is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 7:00 AM (O3: 32.4/100).
Tomorrow (10 August 2026): Air quality in Boulder is fair. All pollutants stay as today. Pollution peaks around 7:00 AM (O3: 33.5/100). Airmine updates local air quality forecasts four times daily.
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Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
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Boulder's air quality benefits from its Front Range position at 1,655 metres with clean Rocky Mountain westerly airflows providing generally excellent ventilation. Vehicle emissions from US-36 are the primary local source, while summer wildfire smoke from Colorado and Wyoming forests is increasingly frequent, and occasional winter Front Range inversions temporarily trap vehicle and wood-burning emissions.
Today - 9 August | Pollution peaks at 07:00
AQI:
Fair
32.4/100
PM2.5 (fine particles):
Good
10.8/100
PM10 (coarse particles):
Good
3.8/100
NO2 (nitrogen dioxide):
Good
15.3/100
O3 (ozone):
Fair
32.4/100
SO2 (sulfur dioxide):
Good
2.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
5.4/100
PM1 (ultrafine particles):
Good
13.9/100
Levels show the poorest local air quality during the day
Tomorrow - 10 August | Pollution peaks at 07:00
AQI:
Fair
33.5/100
PM2.5 (fine particles):
Good
13.7/100
PM10 (coarse particles):
Good
4.2/100
NO2 (nitrogen dioxide):
Good
13.3/100
O3 (ozone):
Fair
33.5/100
SO2 (sulfur dioxide):
Good
1.7/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
4.6/100
PM1 (ultrafine particles):
Good
16.2/100
Pollen forecast in Boulder
View pollen forecastAir quality forecasts for neighbourhoods and landmarks in Boulder
Frequently Asked Questions
Is air quality bad in Boulder right now?
On 9 August 2026, overall air quality in Boulder is fair. AQI is the main air quality indicator at 32.4/100. Pollution peaks around 7:00 AM (O3: 32.4/100).
Will air quality be worse tomorrow in Boulder?
On 10 August 2026, air quality conditions in Boulder will be similar to today, with AQI forecast at fair at 33.5/100. Pollution peaks around 7:00 AM (O3: 33.5/100).
When is air pollution at its worst in Boulder?
Like most US cities, Boulder sees air quality shift from season to season — a brief window in autumn tends to bring the year's best air, before winter inversions set in, whereas summer brings regional wildfire smoke, while winter brings its own inversion-driven pollution episodes. Higher-elevation, more exposed locations generally avoid the worst of the valley inversion episodes.
Are air quality levels in Boulder based on measurements or forecasts?
It is forecasts derived by downscaling forecasts provided by EU’s Copernicus Atmosphere Monitoring Service (CAMS) by taking into account local conditions such as traffic patterns. CAMS bases its forecast on satellite measurements of particles and chemical compounds in the atmosphere. Airmine’s services were developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team.
Why doesn’t the forecast always reflect wildfire impacts?
Airmine’s forecast uses CAMS (Copernicus Atmosphere Monitoring Service) as its background atmospheric model. While CAMS includes wildfire emissions, these are derived from satellite observations and are not available in real time. During rapidly evolving wildfire events, there may therefore be a delay before increased emissions are incorporated into the model. As a result, the forecast may temporarily underestimate PM₂.₅ and other pollutants associated with wildfire smoke.
During rapidly evolving wildfire events, CAMS may lag by approximately 1–2 days before increased wildfire emissions are fully represented, which can lead to temporary underestimation of PM₂.₅ concentrations in Airmine’s forecast.
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Data provided by Airmine — Last update: 9 August 2026 at 20:27 CEST (Data is updated four times daily.)
This forecast is produced independently using Airmine's own atmospheric data and models.
Unless explicitly made clear, the content on this site has not been paid for by external organisations and is Airmine's sole responsibility.
Disclaimer: Forecasts are provided for informational purposes only and should not be relied upon as medical advice. Actual pollen and air quality conditions may vary from the forecast. If you have allergies, asthma, or another medical condition, consult a healthcare professional. Please see our Terms of Service for important information about limitations of liability.
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