Fresno Air Quality in Fall
Across 2019–2025, Fresno's fall (September–November) air quality had a median AQI of 77 (Moderate) over 637 monitored days in the Fresno, CA area. 27.5% of fall days (175 of 637) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 51.3% of days. The cleanest fall on record here was 2025 (median AQI 61, 8 days above 100) and the worst was 2020 (median 117, 50 days above 100, peak AQI 346).
- Good: 14.3%
- Moderate: 58.2%
- Unhealthy for Sensitive Groups: 20.4%
- Unhealthy or worse: 7.1%
Extra Protection for Fresno Homes
Air quality in Fresno is moderate (AQI 69), 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
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Fresno in fall?
Moderate on a typical day: median AQI 77 across 2019–2025, with 27.5% of fall days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓14.3% of fall days were Good (AQI 0–50), 58.2% Moderate (51–100).
- ✓175 days of 637 reached AQI 101+; the fall peak was 346.
- ✓Cleanest month: November; worst month: September.
Frequently asked questions
What is the air quality like in Fresno in fall?▾
Across 2019–2025, the median daily AQI in Fresno in fall was 77 (Moderate). 14.3% of days were Good, 58.2% Moderate, and 27.5% 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 Fresno?▾
A typical fall day in Fresno is Moderate (median AQI 77): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of fall days (27.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Fresno's fall air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 51.3% of fall days in Fresno. The highest fall AQI recorded in 2019–2025 was 346 (Hazardous), in 2020.
Fresno fall air quality, year by year
Fresno fall air quality by year (Fresno, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 91 | 84 | 20 | 187 | O3 |
| 2020worst | 91 | 117 | 50 | 346 | PM2.5 |
| 2021 | 91 | 80 | 31 | 223 | PM2.5 |
| 2022 | 91 | 84 | 26 | 151 | O3 |
| 2023 | 91 | 71 | 14 | 140 | PM2.5 |
| 2024 | 91 | 76 | 26 | 166 | O3 |
| 2025cleanest | 91 | 61 | 8 | 147 | O3 |
What fall air means in Fresno
A typical fall day in Fresno is Moderate (median AQI 77): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 4 of fall days (27.5%) 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 77 is above Fresno's whole-year median of 67, 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 Fresno runs above the national Fall norm; 27.5% of its Fall days topped AQI 100 versus 1.5% nationally (above average).
Within the season, November is the cleanest month (median AQI 76, 16.2% of days above 100) and September the worst (median 88, 39.5% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Fresno
The latest EPA AirNow observation puts Fresno's AQI at 69 (PM10). The figures above are multi-year season statistics, not today's reading.
View current Fresno air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Fresno, 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.