Stockton Air Quality in May
Across 2019–2025, Stockton's May air quality had a median AQI of 44 (Good) over 217 monitored days in the Stockton-Lodi, CA area. 0.5% of May days (1 of 217) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 69.6% of days. The cleanest May on record here was 2023 (median AQI 38, 0 days above 100) and the worst was 2021 (median 52, 1 day above 100, peak AQI 104).
- Good: 77.0%
- Moderate: 22.6%
- 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.
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 May?
Good on a typical day: median AQI 44 across 2019–2025, with 0.5% of May days above AQI 100. Ground-level ozone is the main driver.
- ✓77.0% of May days were Good (AQI 0–50), 22.6% Moderate (51–100).
- ✓1 day of 217 reached AQI 101+; the May peak was 104.
- ✓Best May: 2023; worst May: 2021.
Frequently asked questions
What is the air quality like in Stockton in May?▾
Across 2019–2025, the median daily AQI in Stockton in May was 44 (Good). 77.0% of days were Good, 22.6% Moderate, and 0.5% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is May a good time for outdoor exercise in Stockton?▾
A typical May day in Stockton sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of May days reached AQI 101+ in 2019–2025.
Which pollutant causes Stockton's May air quality problems?▾
Ground-level ozone set the daily AQI on 69.6% of May days in Stockton. The highest May AQI recorded in 2019–2025 was 104 (Unhealthy for Sensitive Groups), in 2021.
Stockton May air quality, year by year
Stockton May air quality by year (Stockton-Lodi, CA, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 44 | 0 | 71 | O3 |
| 2020 | 31 | 42 | 0 | 67 | O3 |
| 2021worst | 31 | 52 | 1 | 104 | PM2.5 |
| 2022 | 31 | 42 | 0 | 100 | O3 |
| 2023cleanest | 31 | 38 | 0 | 56 | O3 |
| 2024 | 31 | 44 | 0 | 56 | O3 |
| 2025 | 31 | 46 | 0 | 57 | O3 |
What May air means in Stockton
A typical May day in Stockton sits in the Good range (median AQI 44), so running, cycling and children's outdoor play are fine for everyone on most days; fewer than 1% of May days reached AQI 101+ in 2019–2025.
May's median AQI of 44 is below Stockton's whole-year median of 48, making it one of the area's cleaner periods. Nationally, the median May AQI across every EPA metro area (104,064 metro-days, 2019–2025) is 44, so Stockton runs in line with the national May norm; 0.5% of its May days topped AQI 100 versus 1.3% nationally (about the same).
May 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.