San Jose Air Quality in November

Across 2019–2025, San Jose's November air quality had a median AQI of 52 (Moderate) over 210 monitored days in the San Jose-Sunnyvale-Santa Clara, CA area. 0.0% of November days (0 of 210) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 75.7% of days. The cleanest November on record here was 2025 (median AQI 35, 0 days above 100) and the worst was 2019 (median 70, 0 days above 100, peak AQI 98).

52
Median AQI
Moderate
0.0%
Days above AQI 100
0 of 210 days
75
90th percentile AQI
worst 1 day in 10
98
Peak AQI
Moderate
PM2.5
Main pollutant
75.7% of days
45.2%
Good days
95 of 210
  • Good: 45.2%
  • Moderate: 54.8%
  • Unhealthy for Sensitive Groups: 0.0%
  • Unhealthy or worse: 0.0%

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QUICK ANSWER

How is the air in San Jose in November?

Moderate on a typical day: median AQI 52 across 2019–2025, with 0.0% of November days above AQI 100. Fine particulate matter (PM2.5) is the main driver.

  • 45.2% of November days were Good (AQI 0–50), 54.8% Moderate (51–100).
  • 0 days of 210 reached AQI 101+; the November peak was 98.
  • Best November: 2025; worst November: 2019.

Frequently asked questions

What is the air quality like in San Jose in November?

Across 2019–2025, the median daily AQI in San Jose in November was 52 (Moderate). 45.2% of days were Good, 54.8% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.

Is November a good time for outdoor exercise in San Jose?

A typical November day in San Jose is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of November days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

Which pollutant causes San Jose's November air quality problems?

Fine particulate matter (PM2.5) set the daily AQI on 75.7% of November days in San Jose. The highest November AQI recorded in 2019–2025 was 98 (Moderate), in 2019.

San Jose November air quality, year by year

San Jose November air quality by year (San Jose-Sunnyvale-Santa Clara, CA, EPA AQS daily AQI)

YearDays monitoredMedian AQIDays above 100Peak AQIMain pollutant
2019worst3070098PM2.5
20203058093PM2.5
20213058086PM2.5
20223054079PM2.5
20233052068PM2.5
20243049078PM2.5
2025cleanest3035044O3

What November air means in San Jose

A typical November day in San Jose is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of November days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.

November's median AQI of 52 is in line with San Jose's whole-year median of 50, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median November AQI across every EPA metro area (92,704 metro-days, 2019–2025) is 39, so San Jose runs above the national November norm; 0.0% of its November days topped AQI 100 versus 0.6% nationally (about the same).

November is part of San Jose's fall season (September, October, November); the fall page pools all three months.

Activity-specific thresholds: running, cycling, kids' sports.

Right now in San Jose

The latest EPA AirNow observation puts San Jose's AQI at 53 (PM2.5). The figures above are multi-year month statistics, not today's reading.

View current San Jose air quality →

Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (San Jose-Sunnyvale-Santa Clara, CA), 2019–2025. Daily AQI per CBSA is the highest AQI reported by any monitor in the area that day; the defining parameter is the pollutant that set it. Month and season statistics pool every such day in the period across all years listed. Retrieved 2026-09-09.