Modesto Air Quality in February
Across 2019–2025, Modesto's February air quality had a median AQI of 52 (Moderate) over 198 monitored days in the Modesto, CA area. 1.5% of February days (3 of 198) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 69.7% of days. The cleanest February on record here was 2019 (median AQI 36, 0 days above 100) and the worst was 2022 (median 75, 2 days above 100, peak AQI 109).
- Good: 49.0%
- Moderate: 49.5%
- Unhealthy for Sensitive Groups: 1.5%
- Unhealthy or worse: 0.0%
Extra Protection for Modesto Homes
Air quality in Modesto is moderate (AQI 63), 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 Modesto in February?
Moderate on a typical day: median AQI 52 across 2019–2025, with 1.5% of February days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓49.0% of February days were Good (AQI 0–50), 49.5% Moderate (51–100).
- ✓3 days of 198 reached AQI 101+; the February peak was 109.
- ✓Best February: 2019; worst February: 2022.
Frequently asked questions
What is the air quality like in Modesto in February?▾
Across 2019–2025, the median daily AQI in Modesto in February was 52 (Moderate). 49.0% of days were Good, 49.5% Moderate, and 1.5% reached Unhealthy for Sensitive Groups or worse, based on 198 monitored days in EPA's Air Quality System.
Is February a good time for outdoor exercise in Modesto?▾
A typical February day in Modesto is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 67 of February days (1.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Modesto's February air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 69.7% of February days in Modesto. The highest February AQI recorded in 2019–2025 was 109 (Unhealthy for Sensitive Groups), in 2022.
Modesto February air quality, year by year
Modesto February air quality by year (Modesto, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019cleanest | 28 | 36 | 0 | 71 | O3 |
| 2020 | 29 | 60 | 0 | 93 | PM2.5 |
| 2021 | 28 | 55 | 1 | 105 | PM2.5 |
| 2022worst | 28 | 75 | 2 | 109 | PM2.5 |
| 2023 | 28 | 58 | 0 | 100 | PM2.5 |
| 2024 | 29 | 38 | 0 | 65 | PM2.5 |
| 2025 | 28 | 38 | 0 | 79 | O3 |
What February air means in Modesto
A typical February day in Modesto is Moderate (median AQI 52): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 67 of February days (1.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
February's median AQI of 52 is in line with Modesto's whole-year median of 54, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median February AQI across every EPA metro area (87,428 metro-days, 2019–2025) is 41, so Modesto runs above the national February norm; 1.5% of its February days topped AQI 100 versus 0.4% nationally (above average).
February is part of Modesto's winter season (December, January, February); the winter page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Modesto
The latest EPA AirNow observation puts Modesto's AQI at 63 (PM10). The figures above are multi-year month statistics, not today's reading.
View current Modesto air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Modesto, 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.