Stockton Air Quality in April
Across 2019–2025, Stockton's April air quality had a median AQI of 43 (Good) over 210 monitored days in the Stockton-Lodi, CA area. 0.5% of April days (1 of 210) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 66.7% of days. The cleanest April on record here was 2020 (median AQI 38, 0 days above 100) and the worst was 2023 (median 42, 1 day above 100, peak AQI 119).
- Good: 78.6%
- Moderate: 21.0%
- Unhealthy for Sensitive Groups: 0.5%
- Unhealthy or worse: 0.0%
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.
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How is the air in Stockton in April?
Good on a typical day: median AQI 43 across 2019–2025, with 0.5% of April days above AQI 100. Ground-level ozone is the main driver.
- ✓78.6% of April days were Good (AQI 0–50), 21.0% Moderate (51–100).
- ✓1 day of 210 reached AQI 101+; the April peak was 119.
- ✓Best April: 2020; worst April: 2023.
Frequently asked questions
What is the air quality like in Stockton in April?▾
Across 2019–2025, the median daily AQI in Stockton in April was 43 (Good). 78.6% of days were Good, 21.0% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 210 monitored days in EPA's Air Quality System.
Is April a good time for outdoor exercise in Stockton?▾
A typical April day in Stockton sits in the Good range (median AQI 43), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of April days reached AQI 101+ in 2019–2025.
Which pollutant causes Stockton's April air quality problems?▾
Ground-level ozone set the daily AQI on 66.7% of April days in Stockton. The highest April AQI recorded in 2019–2025 was 119 (Unhealthy for Sensitive Groups), in 2023.
Stockton April air quality, year by year
Stockton April air quality by year (Stockton-Lodi, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 30 | 44 | 0 | 84 | O3 |
| 2020cleanest | 30 | 38 | 0 | 52 | O3 |
| 2021 | 30 | 47 | 0 | 100 | O3 |
| 2022 | 30 | 42 | 0 | 90 | O3 |
| 2023worst | 30 | 42 | 1 | 119 | O3 |
| 2024 | 30 | 43 | 0 | 61 | PM2.5 |
| 2025 | 30 | 44 | 0 | 57 | O3 |
What April air means in Stockton
A typical April day in Stockton sits in the Good range (median AQI 43), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of April days reached AQI 101+ in 2019–2025.
April's median AQI of 43 is below Stockton's whole-year median of 48, making it one of the area's cleaner periods. Nationally, the median April AQI across every EPA metro area (100,677 metro-days, 2019–2025) is 44, so Stockton runs in line with the national April norm; 0.5% of its April days topped AQI 100 versus 0.7% nationally (about the same).
April is part of Stockton's spring season (March, April, May); the spring page pools all three months.
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 month 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.