Worst air pollution Cupertino, today and tomorrow

Today (15 July): Air quality in Cupertino 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 Cupertino 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.

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

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Cupertino's air quality benefits from the Santa Clara Valley's partial topographic enclosure in Silicon Valley, with vehicle emissions from I-280 and the Apple campus and surrounding technology operations contributing local sources. Bay Delta breezes provide afternoon ventilation, while the Santa Cruz Mountains create topographic variation and summer wildfire smoke from the surrounding Bay Area hills is an increasingly frequent and severe seasonal concern throughout the year.

Today - 15 July | Pollution peaks at 09:00

AQI:

Medium

45.8/100

PM2.5 (fine particles):

Good

16.6/100

PM10 (coarse particles):

Good

10.4/100

NO2 (nitrogen dioxide):

Good

12.7/100

O3 (ozone):

Medium

45.8/100

SO2 (sulfur dioxide):

Good

4.0/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.6/100

PM1 (ultrafine particles):

Good

10.1/100

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

21.4/100

PM10 (coarse particles):

Good

10.8/100

NO2 (nitrogen dioxide):

Fair

20.7/100

O3 (ozone):

Medium

44.7/100

SO2 (sulfur dioxide):

Good

3.8/100

CO (carbon monoxide):

Good

0.0/100

HCHO (formaldehyde):

Good

2.2/100

PM1 (ultrafine particles):

Good

13.8/100

Pollen forecast in Cupertino

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Frequently Asked Questions

Is air quality bad in Cupertino right now?

On 15 July 2026, overall air quality in Cupertino 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 Cupertino?

On 16 July 2026, air quality conditions in Cupertino will be worse than today, with PM2.5 forecast at fair at 21.4/100. Pollution peaks around 9:00 AM (O3: 44.7/100).

When is air pollution at its worst in Cupertino?

Cupertino experiences a distinct seasonal swing in air quality. In short, the shortest stretch of clean air usually falls in the wetter winter months, 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 Cupertino 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?

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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