Stockton Air Quality in Fall
Across 2019–2025, Stockton's fall (September–November) air quality had a median AQI of 55 (Moderate) over 637 monitored days in the Stockton-Lodi, CA area. 4.6% of fall days (29 of 637) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 64.8% of days. The cleanest fall on record here was 2025 (median AQI 48, 0 days above 100) and the worst was 2020 (median 72, 17 days above 100, peak AQI 215).
- Good: 36.6%
- Moderate: 58.9%
- Unhealthy for Sensitive Groups: 2.7%
- Unhealthy or worse: 1.9%
Extra Protection for Stockton Homes
Air quality in Stockton is moderate (AQI 60), with particle pollution the main concern. A True-HEPA purifier gives sensitive groups — kids, seniors and anyone with asthma or allergies — cleaner air indoors on days like today.
Recommended: Coway AP-1512HH Mighty — True HEPA + carbon · CADR ~246 CFM · rooms up to 361 sq ft
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How is the air in Stockton in fall?
Moderate on a typical day: median AQI 55 across 2019–2025, with 4.6% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓36.6% of fall days were Good (AQI 0–50), 58.9% Moderate (51–100).
- ✓29 days of 637 reached AQI 101+; the fall peak was 215.
- ✓Cleanest month: November; worst month: September.
Frequently asked questions
What is the air quality like in Stockton in fall?▾
Across 2019–2025, the median daily AQI in Stockton in fall was 55 (Moderate). 36.6% of days were Good, 58.9% Moderate, and 4.6% reached Unhealthy for Sensitive Groups or worse, based on 637 monitored days in EPA's Air Quality System.
Is fall a good time for outdoor exercise in Stockton?▾
A typical fall day in Stockton is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 22 of fall days (4.6%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Stockton's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 64.8% of fall days in Stockton. The highest fall AQI recorded in 2019–2025 was 215 (Very Unhealthy), in 2020.
Stockton fall air quality, year by year
Stockton fall air quality by year (Stockton-Lodi, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 91 | 55 | 2 | 190 | PM2.5 |
| 2020worst | 91 | 72 | 17 | 215 | PM2.5 |
| 2021 | 91 | 60 | 3 | 124 | PM2.5 |
| 2022 | 91 | 54 | 3 | 208 | PM2.5 |
| 2023 | 91 | 53 | 1 | 107 | PM2.5 |
| 2024 | 91 | 52 | 3 | 140 | PM2.5 |
| 2025cleanest | 91 | 48 | 0 | 82 | PM2.5 |
What fall air means in Stockton
A typical fall day in Stockton is Moderate (median AQI 55): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 22 of fall days (4.6%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Fall's median AQI of 55 is above Stockton's whole-year median of 48, making it one of the area's dirtier periods. Nationally, the median Fall AQI across every EPA metro area (296,275 metro-days, 2019–2025) is 40, so Stockton runs above the national Fall norm; 4.6% of its Fall days topped AQI 100 versus 1.5% nationally (above average).
Within the season, November is the cleanest month (median AQI 64, 2.9% of days above 100) and September the worst (median 52, 6.7% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Stockton
The latest EPA AirNow observation puts Stockton's AQI at 60 (PM10). The figures above are multi-year season statistics, not today's reading.
View current Stockton air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Stockton-Lodi, 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.