St. Louis Air Quality in 2022
In 2022, St. Louis's air quality (St. Louis, MO-IL area) had a median daily AQI of 58 (Moderate) across 365 monitored days. 15 days (4.1%) reached Unhealthy for Sensitive Groups or worse, 81 were Good, and the year's peak AQI was 147 (Unhealthy for Sensitive Groups). Fine particulate matter (PM2.5) set the daily AQI on 259 of those days. The cleanest month of 2022 was April (median AQI 53, 0 days above 100) and the worst was June (median 77, 9 days above 100, peak 147).
- Good: 22.2%
- Moderate: 73.7%
- Unhealthy for Sensitive Groups: 4.1%
- Unhealthy or worse: 0.0%
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How was St. Louis's air quality in 2022?
Moderate on a typical day: median AQI 58, with 15 days above AQI 100 out of 365 monitored — the 4th cleanest of 7 years on record for the area.
- ✓Peak AQI in 2022: 147 (Unhealthy for Sensitive Groups).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 259 days.
- ✓Cleanest month: April; worst: June.
Frequently asked questions
What was the average AQI in St. Louis in 2022?▾
EPA's Air Quality System puts St. Louis's (St. Louis, MO-IL) median daily AQI for 2022 at 58, which is Moderate. 15 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 147.
Which month had the worst air quality in St. Louis in 2022?▾
The cleanest month of 2022 was April (median AQI 53, 0 days above 100) and the worst was June (median 77, 9 days above 100, peak 147).
Was 2022 a good or bad year for St. Louis's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2022 ranks 4th cleanest by days above AQI 100. 2022's median of 58 is in line with the area's typical annual median of 58.
St. Louis month by month in 2022
St. Louis air quality month by month, 2022 (St. Louis, MO-IL, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 57 | 0 | 88 | PM2.5 |
| February | 28 | 58 | 0 | 82 | PM2.5 |
| March | 31 | 54 | 0 | 87 | PM2.5 |
| Aprilcleanest | 30 | 53 | 0 | 89 | PM2.5 |
| May | 31 | 55 | 0 | 100 | PM2.5 |
| Juneworst | 30 | 77 | 9 | 147 | O3 |
| July | 31 | 64 | 3 | 140 | O3 |
| August | 31 | 57 | 0 | 80 | PM2.5 |
| September | 30 | 57 | 0 | 97 | PM2.5 |
| October | 31 | 56 | 1 | 111 | PM2.5 |
| November | 30 | 58 | 1 | 109 | PM2.5 |
| December | 31 | 58 | 1 | 103 | PM2.5 |
How 2022 compares
Among the 7 years EPA has published for the area (2019–2025), 2022 ranks 4th cleanest by days above AQI 100.
2022's median of 58 is in line with the area's typical annual median of 58.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in St. Louis
The latest EPA AirNow observation puts St. Louis's AQI at 39 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current St. Louis air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (St. Louis, MO-IL), 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.