Worst air pollution Napa, today and tomorrow

Today (15 July): Air quality in Napa is fair. PM2.5 and O3 are fair; AQI and NO2 are medium; PM10, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 10:00 PM (NO2: 43.5/100).
Tomorrow (16 July 2026): Air quality in Napa is fair. PM1 increases to fair; all other pollutants stay as today. Pollution peaks around 10:00 PM (NO2: 56.1/100). 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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Napa's air quality reflects the Napa Valley's partial topographic enclosure between the Mayacamas and Vaca mountains, with vehicle emissions from CA-29 and the surrounding Napa Valley wine country operations contributing local sources. Summer wildfire smoke from the surrounding Wine Country ranges is a severe and recurring seasonal concern, while the Petaluma Gap Delta breeze provides afternoon ventilation and the valley's enclosed character creates periodic temperature inversion episodes.

Today - 15 July | Pollution peaks at 22:00

AQI:

Medium

43.5/100

PM2.5 (fine particles):

Fair

21.5/100

PM10 (coarse particles):

Good

14.7/100

NO2 (nitrogen dioxide):

Medium

43.5/100

O3 (ozone):

Fair

33.8/100

SO2 (sulfur dioxide):

Good

9.2/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

1.7/100

PM1 (ultrafine particles):

Good

12.8/100

Levels show the poorest local air quality during the day

Tomorrow - 16 July | Pollution peaks at 22:00

AQI:

Medium

56.1/100

PM2.5 (fine particles):

Fair

32.7/100

PM10 (coarse particles):

Good

18.8/100

NO2 (nitrogen dioxide):

Medium

56.1/100

O3 (ozone):

Fair

32.8/100

SO2 (sulfur dioxide):

Good

13.3/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.7/100

PM1 (ultrafine particles):

Fair

22.6/100

Pollen forecast in Napa

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Air quality forecasts for neighbourhoods and landmarks in Napa

Sports venues in Napa

Frequently Asked Questions

Is air quality bad in Napa right now?

On 15 July 2026, overall air quality in Napa is fair. O3 is the main pollutant at 33.8/100. Pollution peaks around 10:00 PM (NO2: 43.5/100).

Will air quality be worse tomorrow in Napa?

On 16 July 2026, air quality conditions in Napa will be similar to today, with O3 forecast at fair at 32.8/100. Pollution peaks around 10:00 PM (NO2: 56.1/100).

When is air pollution at its worst in Napa?

Air quality across Napa rises and falls with the seasons. In short, the rainy winter months generally bring the cleanest air, as storms clear traffic and woodsmoke pollution, whereas summer and early autumn bring the highest risk, with heat-driven ozone and wildfire smoke both peaking from July through October. Wine country and inland valley locations tend to see more smoke buildup than the immediate coast.

Are air quality levels in Napa 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