Worst air pollution San Francisco, today and tomorrow
Today (15 July): Air quality in San Francisco is fair. AQI and O3 are fair; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 8:00 AM (O3: 39.4/100).
Tomorrow (16 July 2026): Air quality in San Francisco is medium. AQI improves to medium; O3 decreases to medium; all other pollutants stay as today. Pollution peaks around 10:00 AM (O3: 41.0/100). Airmine updates local air quality forecasts four times daily.
For long term forecasts and maps, see the Airmine app
Developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team
Use our Strava plugin to check your own exposure.
San Francisco's air quality benefits from Pacific Ocean winds and Bay breezes that provide reliable natural ventilation across the peninsula. The primary recurring threat is wildfire smoke from the broader California fire season, which can dramatically elevate PM2.5. Localised topographic variation creates significant differences between the sheltered eastern neighbourhoods and the exposed western and northern waterfront.
Today - 15 July | Pollution peaks at 08:00
AQI:
Fair
39.4/100
PM2.5 (fine particles):
Good
12.9/100
PM10 (coarse particles):
Good
7.9/100
NO2 (nitrogen dioxide):
Good
3.0/100
O3 (ozone):
Fair
39.4/100
SO2 (sulfur dioxide):
Good
1.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.2/100
PM1 (ultrafine particles):
Good
7.1/100
Levels show the poorest local air quality during the day
Tomorrow - 16 July | Pollution peaks at 10:00
AQI:
Medium
41.0/100
PM2.5 (fine particles):
Good
17.9/100
PM10 (coarse particles):
Good
8.7/100
NO2 (nitrogen dioxide):
Good
6.5/100
O3 (ozone):
Medium
41.0/100
SO2 (sulfur dioxide):
Good
1.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
1.9/100
PM1 (ultrafine particles):
Good
11.8/100
Pollen forecast in San Francisco
View pollen forecastAir quality forecasts for neighbourhoods and landmarks in San Francisco
Sports venues in San Francisco
Frequently Asked Questions
Is air quality bad in San Francisco right now?
On 15 July 2026, overall air quality in San Francisco is fair. AQI is the main air quality indicator at 39.4/100. Pollution peaks around 8:00 AM (O3: 39.4/100).
Will air quality be worse tomorrow in San Francisco?
On 16 July 2026, air quality conditions in San Francisco will be better than today, with AQI forecast at medium at 41.0/100. Pollution peaks around 10:00 AM (O3: 41.0/100).
When is air pollution at its worst in San Francisco?
Air quality in San Francisco shifts across the year. Typically, late winter and spring tend to have the cleanest conditions, once winter rains settle in, while 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 San Francisco 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?
Check air quality in other popular cities:
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