Worst air pollution Boulder, today and tomorrow

Today (16 July): Air quality in Boulder is fair. AQI, NO2, and O3 are fair; PM2.5, PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 6:00 AM (O3: 34.1/100).
Tomorrow (17 July 2026): Air quality in Boulder is fair. NO2 decreases to good; all other pollutants stay as today. Pollution peaks around 6:00 AM (O3: 38.0/100). 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 - 16 July | Pollution peaks at 06:00

AQI:

Fair

34.1/100

PM2.5 (fine particles):

Good

12.6/100

PM10 (coarse particles):

Good

11.5/100

NO2 (nitrogen dioxide):

Fair

20.9/100

O3 (ozone):

Fair

34.1/100

SO2 (sulfur dioxide):

Good

3.1/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

4.9/100

PM1 (ultrafine particles):

Good

8.0/100

Levels show the poorest local air quality during the day

Tomorrow - 17 July | Pollution peaks at 06:00

AQI:

Fair

38.0/100

PM2.5 (fine particles):

Good

13.6/100

PM10 (coarse particles):

Good

7.8/100

NO2 (nitrogen dioxide):

Good

12.7/100

O3 (ozone):

Fair

38.0/100

SO2 (sulfur dioxide):

Good

1.9/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

5.6/100

PM1 (ultrafine particles):

Good

8.7/100

Pollen forecast in Boulder

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Air quality forecasts for neighbourhoods and landmarks in Boulder

Frequently Asked Questions

Is air quality bad in Boulder right now?

On 16 July 2026, overall air quality in Boulder is fair. AQI is the main air quality indicator at 34.1/100. Pollution peaks around 6:00 AM (O3: 34.1/100).

Will air quality be worse tomorrow in Boulder?

On 17 July 2026, air quality conditions in Boulder will be similar to today, with AQI forecast at fair at 38.0/100. Pollution peaks around 6:00 AM (O3: 38.0/100).

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.

Want to see air quality forecasts for other cities in United States?

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Data provided by Airmine — Last update: 16 July 2026 at 10:33 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.

For long term forecasts and maps, see the Airmine app