Worst air pollution Chico, today and tomorrow

Today (15 July): Air quality in Chico is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 8:00 AM (O3: 41.2/100).
Tomorrow (16 July 2026): Air quality in Chico is fair. AQI worsens to fair; O3 increases to fair; all other pollutants stay as today. Pollution peaks around 11:00 AM (O3: 37.2/100). 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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Chico's air quality reflects the Sacramento Valley's temperature inversion problem, with vehicle emissions from SR-99 and surrounding Butte County almond and rice farming contributing agricultural burning PM2.5 during the autumn harvest season. Winter tule fog inversions trap vehicle and agricultural emissions, while the Paradise Ridge to the east creates topographic variation and summer wildfire smoke from the surrounding Sierra foothills is an increasingly severe concern.

Today - 15 July | Pollution peaks at 08:00

AQI:

Medium

41.2/100

PM2.5 (fine particles):

Good

12.9/100

PM10 (coarse particles):

Good

5.6/100

NO2 (nitrogen dioxide):

Good

3.5/100

O3 (ozone):

Medium

41.2/100

SO2 (sulfur dioxide):

Good

0.7/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.9/100

PM1 (ultrafine particles):

Good

9.3/100

Levels show the poorest local air quality during the day

Tomorrow - 16 July | Pollution peaks at 11:00

AQI:

Fair

37.2/100

PM2.5 (fine particles):

Good

13.1/100

PM10 (coarse particles):

Good

10.0/100

NO2 (nitrogen dioxide):

Good

5.3/100

O3 (ozone):

Fair

37.2/100

SO2 (sulfur dioxide):

Good

0.8/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

4.1/100

PM1 (ultrafine particles):

Good

8.7/100

Pollen forecast in Chico

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Frequently Asked Questions

Is air quality bad in Chico right now?

On 15 July 2026, overall air quality in Chico is medium. AQI is the main air quality indicator at 41.2/100. Pollution peaks around 8:00 AM (O3: 41.2/100).

Will air quality be worse tomorrow in Chico?

On 16 July 2026, air quality conditions in Chico will be worse than today, with AQI forecast at fair at 37.2/100. Pollution peaks around 11:00 AM (O3: 37.2/100).

When is air pollution at its worst in Chico?

Chico follows a fairly predictable seasonal air quality pattern, as late winter and spring tend to have the cleanest conditions, once winter rains settle in; by contrast, the long dry stretch from midsummer into autumn brings both ozone and wildfire smoke risk. Dry summer conditions with virtually no rain mean pollution and smoke can linger for extended stretches once they arrive.

Are air quality levels in Chico 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.

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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