Worst air pollution Costa Mesa, today and tomorrow
Today (15 July): Air quality in Costa Mesa is fair. AQI, PM10, and O3 are fair; PM2.5, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 7:00 AM (O3: 30.4/100).
Tomorrow (16 July 2026): Air quality in Costa Mesa is fair. All pollutants stay as today. Pollution peaks around 9:00 AM (O3: 29.7/100). 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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Costa Mesa's air quality benefits from its Orange County coastal position, with consistent Pacific sea breezes from the Newport Bay area providing reliable maritime ventilation. Vehicle emissions from SR-55 and I-405 are the primary local sources, while the coastal proximity generally provides noticeably better conditions than the deeper Los Angeles basin and the John Wayne Airport contributes localised aviation NOₓ.
Today - 15 July | Pollution peaks at 07:00
AQI:
Fair
30.4/100
PM2.5 (fine particles):
Good
14.7/100
PM10 (coarse particles):
Fair
23.2/100
NO2 (nitrogen dioxide):
Good
0.3/100
O3 (ozone):
Fair
30.4/100
SO2 (sulfur dioxide):
Good
0.8/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
0.9/100
PM1 (ultrafine particles):
Good
2.7/100
Levels show the poorest local air quality during the day
Tomorrow - 16 July | Pollution peaks at 09:00
AQI:
Fair
29.7/100
PM2.5 (fine particles):
Good
12.0/100
PM10 (coarse particles):
Fair
20.2/100
NO2 (nitrogen dioxide):
Good
0.4/100
O3 (ozone):
Fair
29.7/100
SO2 (sulfur dioxide):
Good
1.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
0.9/100
PM1 (ultrafine particles):
Good
2.7/100
Pollen forecast in Costa Mesa
View pollen forecastFrequently Asked Questions
Is air quality bad in Costa Mesa right now?
On 15 July 2026, overall air quality in Costa Mesa is fair. AQI is the main air quality indicator at 30.4/100. Pollution peaks around 7:00 AM (O3: 30.4/100).
Will air quality be worse tomorrow in Costa Mesa?
On 16 July 2026, air quality conditions in Costa Mesa will be similar to today, with AQI forecast at fair at 29.7/100. Pollution peaks around 9:00 AM (O3: 29.7/100).
When is air pollution at its worst in Costa Mesa?
Conditions in Costa Mesa vary noticeably across the seasons. In short, winter typically brings the cleanest stretch, once occasional rain clears the basin, whereas from August into October, wildfire smoke can add sharp particulate spikes on top of the usual summer ozone. The mountains ringing the basin can trap pollution close to the ground for days when winds are calm.
Are air quality levels in Costa Mesa 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