Worst air pollution Simi Valley, today and tomorrow
Today (15 July): Air quality in Simi Valley is fair. AQI, PM2.5, PM10, and O3 are fair; NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 8:00 AM (O3: 32.2/100).
Tomorrow (16 July 2026): Air quality in Simi Valley is fair. PM2.5 decreases to good; all other pollutants stay as today. Pollution peaks around 9:00 AM (O3: 30.3/100). 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.
Simi Valley's air quality reflects partial topographic enclosure between the Santa Susana Mountains and Simi Hills, with vehicle emissions from SR-118 the primary local source. The valley receives accumulated Los Angeles basin pollution under inversions, while the Simi Pass and Santa Ana winds provide periodic flushing of valley emissions throughout the year.
Today - 15 July | Pollution peaks at 08:00
AQI:
Fair
32.2/100
PM2.5 (fine particles):
Fair
20.5/100
PM10 (coarse particles):
Fair
27.0/100
NO2 (nitrogen dioxide):
Good
1.6/100
O3 (ozone):
Fair
32.2/100
SO2 (sulfur dioxide):
Good
2.3/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
1.5/100
PM1 (ultrafine particles):
Good
4.3/100
Levels show the poorest local air quality during the day
Tomorrow - 16 July | Pollution peaks at 09:00
AQI:
Fair
30.3/100
PM2.5 (fine particles):
Good
18.2/100
PM10 (coarse particles):
Fair
28.8/100
NO2 (nitrogen dioxide):
Good
2.4/100
O3 (ozone):
Fair
30.3/100
SO2 (sulfur dioxide):
Good
3.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
1.4/100
PM1 (ultrafine particles):
Good
5.0/100
Pollen forecast in Simi Valley
View pollen forecastSports venues in Simi Valley
Frequently Asked Questions
Is air quality bad in Simi Valley right now?
On 15 July 2026, overall air quality in Simi Valley is fair. AQI is the main air quality indicator at 32.2/100. Pollution peaks around 8:00 AM (O3: 32.2/100).
Will air quality be worse tomorrow in Simi Valley?
On 16 July 2026, air quality conditions in Simi Valley will be similar to today, with AQI forecast at fair at 30.3/100. Pollution peaks around 9:00 AM (O3: 30.3/100).
When is air pollution at its worst in Simi Valley?
Air quality in Simi Valley shifts across the year — winter typically brings the cleanest stretch, once occasional rain clears the basin, whereas summer and early autumn bring the highest ozone levels, and wildfire smoke can spike particulate readings sharply from August through October. The mountains ringing the basin can trap pollution close to the ground for days when winds are calm.
Are air quality levels in Simi Valley 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