Pittsburgh Air Quality in 2021
In 2021, Pittsburgh's air quality (Pittsburgh, PA area) had a median daily AQI of 58 (Moderate) across 365 monitored days. 9 days (2.5%) reached Unhealthy for Sensitive Groups or worse, 102 were Good, and the year's peak AQI was 154 (Unhealthy). Fine particulate matter (PM2.5) set the daily AQI on 302 of those days. The cleanest month of 2021 was October (median AQI 48, 0 days above 100) and the worst was July (median 60, 3 days above 100, peak 154).
- Good: 27.9%
- Moderate: 69.6%
- Unhealthy for Sensitive Groups: 2.2%
- Unhealthy or worse: 0.3%
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How was Pittsburgh's air quality in 2021?
Moderate on a typical day: median AQI 58, with 9 days above AQI 100 out of 365 monitored — the 2nd cleanest of 7 years on record for the area.
- ✓Peak AQI in 2021: 154 (Unhealthy).
- ✓Fine particulate matter (PM2.5) was the main pollutant on 302 days.
- ✓Cleanest month: October; worst: July.
Frequently asked questions
What was the average AQI in Pittsburgh in 2021?▾
EPA's Air Quality System puts Pittsburgh's (Pittsburgh, PA) median daily AQI for 2021 at 58, which is Moderate. 9 days were Unhealthy for Sensitive Groups or worse and the year's highest AQI was 154.
Which month had the worst air quality in Pittsburgh in 2021?▾
The cleanest month of 2021 was October (median AQI 48, 0 days above 100) and the worst was July (median 60, 3 days above 100, peak 154).
Was 2021 a good or bad year for Pittsburgh's air?▾
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 2nd cleanest by days above AQI 100. 2021's median of 58 is in line with the area's typical annual median of 58.
Pittsburgh month by month in 2021
Pittsburgh air quality month by month, 2021 (Pittsburgh, PA, EPA AQS daily AQI)
| Month | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| January | 31 | 54 | 0 | 90 | PM2.5 |
| February | 28 | 58 | 0 | 95 | PM2.5 |
| March | 31 | 52 | 1 | 123 | PM2.5 |
| April | 30 | 55 | 1 | 108 | PM2.5 |
| May | 31 | 58 | 1 | 105 | PM2.5 |
| June | 30 | 60 | 0 | 100 | PM2.5 |
| Julyworst | 31 | 60 | 3 | 154 | PM2.5 |
| August | 31 | 64 | 1 | 105 | PM2.5 |
| September | 30 | 58 | 0 | 71 | PM2.5 |
| Octobercleanest | 31 | 48 | 0 | 90 | PM2.5 |
| November | 30 | 58 | 1 | 146 | PM2.5 |
| December | 31 | 61 | 1 | 107 | PM2.5 |
How 2021 compares
Among the 7 years EPA has published for the area (2019–2025), 2021 ranks 2nd cleanest by days above AQI 100.
2021'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 Pittsburgh
The latest EPA AirNow observation puts Pittsburgh's AQI at 53 (PM2.5). The figures above are multi-year annual statistics, not today's reading.
View current Pittsburgh air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Pittsburgh, PA), 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.