City in California, United States
Air quality in San Jose
Moderate
The annual average PM2.5 in San Jose was 12.5 µg/m³ in 2022, about 2.5 times the WHO guideline of 5 µg/m³. Wildfire smoke can cause unhealthy days in Aug–Oct; otherwise air is usually good.
Key facts
- PM2.5: 12.5 µg/m³ yearly average (2022). Measured at San Jose Sunnyvale Santa Clara CA, 1 km away.
- Nitrogen dioxide: 19.1 µg/m³ (2022), mostly from traffic.
- Worst months: Sep–Oct.
Air quality across United States
| Place | PM2.5 | Level |
|---|---|---|
| Maui | 2 µg/m³ | Meets the WHO guideline |
| Honolulu | 3 µg/m³ | Meets the WHO guideline |
| Kauai | 3 µg/m³ | Meets the WHO guideline |
| Big Island | 3 µg/m³ | Meets the WHO guideline |
| Lake Tahoe | 5.2 µg/m³ | Fairly clean |
| Portland | 5.8 µg/m³ | Fairly clean |
| Denver | 6 µg/m³ | Fairly clean |
| Seattle | 6.1 µg/m³ | Fairly clean |
| Miami | 6.2 µg/m³ | Fairly clean |
| Miami Beach | 6.2 µg/m³ | Fairly clean |
| Washington, D.C. | 6.3 µg/m³ | Fairly clean |
| Boston | 6.4 µg/m³ | Fairly clean |
| Orlando | 6.7 µg/m³ | Fairly clean |
| New York City | 7.1 µg/m³ | Fairly clean |
| Philadelphia | 7.2 µg/m³ | Fairly clean |
| Charleston | 7.3 µg/m³ | Fairly clean |
| Nashville | 7.7 µg/m³ | Fairly clean |
| Scottsdale | 8 µg/m³ | Fairly clean |
| Napa Valley | 8 µg/m³ | Fairly clean |
| New Orleans | 8.2 µg/m³ | Fairly clean |
| San Diego | 8.2 µg/m³ | Fairly clean |
| Atlanta | 8.5 µg/m³ | Fairly clean |
| Dallas | 8.5 µg/m³ | Fairly clean |
| Chicago | 8.7 µg/m³ | Fairly clean |
| Austin | 9 µg/m³ | Fairly clean |
| San Antonio | 9 µg/m³ | Fairly clean |
| Las Vegas | 9.7 µg/m³ | Fairly clean |
| Los Angeles | 10.5 µg/m³ | Moderate |
| Houston | 11.1 µg/m³ | Moderate |
| San Jose | 12.5 µg/m³ | Moderate |
Quick answers
Is the air in San Jose bad?
Moderate: 12.5 µg/m³ of PM2.5 on average, 2.5× the WHO guideline. It's usually worst in Sep–Oct.
When is the air worst in San Jose?
Wildfire smoke can cause unhealthy days in Aug–Oct; otherwise air is usually good.
How does San Jose compare with the rest of United States?
People in United States breathe 7 µg/m³ of PM2.5 on average (2023, World Bank/WHO), against 12.5 µg/m³ measured here.
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Sources
- WHO Ambient Air Quality Database
- WHO air quality guidelines (2021)
- Live air quality map (WAQI)
- VTA (Santa Clara Valley Transportation Authority)
- Caltrain
- San José Mineta International Airport
- Visit San José
Annual averages are measured values reported to the WHO; check a live map for today's air. Compiled and reviewed by SoloSquare. How we compile and score this. Spotted something out of date? Tell us.