Fresno Air Quality in Winter
Across 2019–2025, Fresno's winter (December–February) air quality had a median AQI of 68 (Moderate) over 632 monitored days in the Fresno, CA area. 13.0% of winter days (82 of 632) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 88.9% of days. The cleanest winter on record here was 2025 (median AQI 70, 6 days above 100) and the worst was 2022 (median 86, 19 days above 100, peak AQI 145).
- Good: 19.5%
- Moderate: 67.6%
- Unhealthy for Sensitive Groups: 12.2%
- Unhealthy or worse: 0.8%
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.
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How is the air in Fresno in winter?
Moderate on a typical day: median AQI 68 across 2019–2025, with 13.0% of winter days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓19.5% of winter days were Good (AQI 0–50), 67.6% Moderate (51–100).
- ✓82 days of 632 reached AQI 101+; the winter peak was 278.
- ✓Cleanest month: February; worst month: December.
Frequently asked questions
What is the air quality like in Fresno in winter?▾
Across 2019–2025, the median daily AQI in Fresno in winter was 68 (Moderate). 19.5% of days were Good, 67.6% Moderate, and 13.0% reached Unhealthy for Sensitive Groups or worse, based on 632 monitored days in EPA's Air Quality System.
Is winter a good time for outdoor exercise in Fresno?▾
A typical winter day in Fresno is Moderate (median AQI 68): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 8 of winter days (13.0%) 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 winter air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 88.9% of winter days in Fresno. The highest winter AQI recorded in 2019–2025 was 278 (Very Unhealthy), in 2022.
Fresno winter air quality, year by year
Fresno winter air quality by year (Fresno, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 90 | 57 | 10 | 140 | PM2.5 |
| 2020 | 91 | 73 | 13 | 130 | PM2.5 |
| 2021 | 90 | 67 | 14 | 278 | PM2.5 |
| 2022worst | 90 | 86 | 19 | 145 | PM2.5 |
| 2023 | 90 | 60 | 11 | 140 | PM2.5 |
| 2024 | 91 | 64 | 9 | 156 | PM2.5 |
| 2025cleanest | 90 | 70 | 6 | 157 | PM2.5 |
What winter air means in Fresno
A typical winter day in Fresno is Moderate (median AQI 68): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 8 of winter days (13.0%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Winter's median AQI of 68 is in line with Fresno's whole-year median of 67, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median Winter AQI across every EPA metro area (278,620 metro-days, 2019–2025) is 40, so Fresno runs above the national Winter norm; 13.0% of its Winter days topped AQI 100 versus 0.6% nationally (above average).
Within the season, February is the cleanest month (median AQI 59, 2.0% of days above 100) and December the worst (median 73, 18.4% 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.