Worst air pollution Gilroy, today and tomorrow
Today (15 July): Air quality in Gilroy is medium. AQI and O3 are medium; PM2.5, PM10, NO2, SO2, CO, HCHO, and PM1 are good. Pollution peaks around 9:00 AM (O3: 45.8/100).
Tomorrow (16 July 2026): Air quality in Gilroy is fair. PM2.5 increases to fair; NO2 increases to fair; all other pollutants stay as today. Pollution peaks around 9:00 AM (O3: 44.7/100). 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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Gilroy's air quality reflects the southern Santa Clara Valley's partial topographic enclosure between the Diablo Range and Santa Cruz Mountains, with vehicle emissions from US-101 and garlic farming and food processing VOCs contributing local sources. Summer wildfire smoke from the surrounding coastal mountains is an increasingly frequent seasonal concern throughout the year.
Today - 15 July | Pollution peaks at 09:00
AQI:
Medium
45.8/100
PM2.5 (fine particles):
Good
18.3/100
PM10 (coarse particles):
Good
11.5/100
NO2 (nitrogen dioxide):
Good
17.0/100
O3 (ozone):
Medium
45.8/100
SO2 (sulfur dioxide):
Good
5.4/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.6/100
PM1 (ultrafine particles):
Good
11.1/100
Levels show the poorest local air quality during the day
Tomorrow - 16 July | Pollution peaks at 09:00
AQI:
Medium
44.7/100
PM2.5 (fine particles):
Fair
23.3/100
PM10 (coarse particles):
Good
11.9/100
NO2 (nitrogen dioxide):
Fair
25.9/100
O3 (ozone):
Medium
44.7/100
SO2 (sulfur dioxide):
Good
5.1/100
CO (carbon monoxide):
Good
0.0/100
HCHO (formaldehyde):
Good
2.2/100
PM1 (ultrafine particles):
Good
15.2/100
Pollen forecast in Gilroy
View pollen forecastFrequently Asked Questions
Is air quality bad in Gilroy right now?
On 15 July 2026, overall air quality in Gilroy is medium. AQI is the main air quality indicator at 45.8/100. Pollution peaks around 9:00 AM (O3: 45.8/100).
Will air quality be worse tomorrow in Gilroy?
On 16 July 2026, air quality conditions in Gilroy will be worse than today, with NO2 forecast at fair at 25.9/100. Pollution peaks around 9:00 AM (O3: 44.7/100).
When is air pollution at its worst in Gilroy?
Gilroy sees air quality change through the year. In short, the shortest stretch of clean air usually falls in the wetter winter months, 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 Gilroy 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