Stockton Air Quality in 2019
In 2019, Stockton's air quality (Stockton-Lodi, CA area) had a median daily AQI of 47 (Good) across 365 monitored days. 12 days (3.3%) reached Unhealthy for Sensitive Groups or worse, 202 were Good, and the year's peak AQI was 190 (Unhealthy). Ground-level ozone set the daily AQI on 201 of those days. The cleanest month of 2019 was February (median AQI 41, 0 days above 100) and the worst was January (median 64, 7 days above 100, peak 137).
- Good: 55.3%
- Moderate: 41.4%
- Unhealthy for Sensitive Groups: 3.0%
- Unhealthy or worse: 0.3%
Improve Indoor Air Quality
Even with good outdoor air in Stockton, indoor PM2.5, dust and allergens build up. A True-HEPA purifier keeps a bedroom or office consistently clean.
Recommended: Levoit Core 400S — True HEPA · CADR ~141 CFM · rooms up to 219 sq ft
As an Amazon Associate, we earn from qualifying purchases.
How was Stockton's air quality in 2019?
Good on a typical day: median AQI 47, with 12 days above AQI 100 out of 365 monitored — the 5th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2019: 190 (Unhealthy).
- ✓Ground-level ozone was the main pollutant on 201 days.
- ✓Cleanest month: February; worst: January.
Frequently asked questions
What was the average AQI in Stockton in 2019?▾
EPA's Air Quality System puts Stockton's (Stockton-Lodi, CA) median daily AQI for 2019 at 47, which is Good. 12 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 190.
Which month had the worst air quality in Stockton in 2019?▾
The cleanest month of 2019 was February (median AQI 41, 0 days above 100) and the worst was January (median 64, 7 days above 100, peak 137).
Was 2019 a good or bad year for Stockton's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 5th cleanest by days above AQI 100. 2019's median of 47 is in line with the area's typical annual median of 48.
Stockton month by month in 2019
Stockton air quality month by month, 2019 (Stockton-Lodi, CA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| Januaryworst | 31 | 64 | 7 | 137 | PM2.5 |
| Februarycleanest | 28 | 41 | 0 | 75 | O3 |
| March | 31 | 41 | 0 | 72 | O3 |
| April | 30 | 44 | 0 | 84 | O3 |
| May | 31 | 44 | 0 | 71 | O3 |
| June | 30 | 46 | 1 | 112 | O3 |
| July | 31 | 47 | 1 | 129 | O3 |
| August | 31 | 51 | 1 | 115 | O3 |
| September | 30 | 39 | 1 | 122 | O3 |
| October | 31 | 55 | 1 | 190 | PM2.5 |
| November | 30 | 75 | 0 | 95 | PM2.5 |
| December | 31 | 53 | 0 | 86 | PM2.5 |
How 2019 compares
Among the 7 years EPA has published for the area (2019–2025), 2019 ranks 5th cleanest by days above AQI 100.
2019's median of 47 is in line with the area's typical annual median of 48.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Stockton
The latest EPA AirNow observation puts Stockton's AQI at 49 (PM2.5). The figures above are multi-year annual 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.