Philadelphia Air Quality in August
Across 2019–2025, Philadelphia's August air quality had a median AQI of 58 (Moderate) over 217 monitored days in the Philadelphia-Camden-Wilmington, PA-NJ-DE-MD area. 6.5% of August days (14 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 54.8% of days. The cleanest August on record here was 2022 (median AQI 52, 0 days above 100) and the worst was 2021 (median 60, 4 days above 100, peak AQI 151).
- Good: 29.0%
- Moderate: 64.5%
- Unhealthy for Sensitive Groups: 6.0%
- Unhealthy or worse: 0.5%
Reduce Indoor Ozone in Philadelphia
Today's main pollutant in Philadelphia is ground-level ozone (AQI 26). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.
Recommended: Levoit Core 300 — True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft
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How is the air in Philadelphia in August?
Moderate on a typical day: median AQI 58 across 2019–2025, with 6.5% of August days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓29.0% of August days were Good (AQI 0–50), 64.5% Moderate (51–100).
- ✓14 days of 217 reached AQI 101+; the August peak was 151.
- ✓Best August: 2022; worst August: 2021.
Frequently asked questions
What is the air quality like in Philadelphia in August?▾
Across 2019–2025, the median daily AQI in Philadelphia in August was 58 (Moderate). 29.0% of days were Good, 64.5% Moderate, and 6.5% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is August a good time for outdoor exercise in Philadelphia?▾
A typical August day in Philadelphia is Moderate (median AQI 58): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 15 of August days (6.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Which pollutant causes Philadelphia's August air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 54.8% of August days in Philadelphia. The highest August AQI recorded in 2019–2025 was 151 (Unhealthy), in 2021.
Philadelphia August air quality, year by year
Philadelphia August air quality by year (Philadelphia-Camden-Wilmington, PA-NJ-DE-MD, EPA AQS daily AQI)
| Year | Days monitored | Median AQI | Days above 100 | Peak AQI | Main pollutant |
|---|---|---|---|---|---|
| 2019 | 31 | 59 | 1 | 105 | PM2.5 |
| 2020 | 31 | 57 | 1 | 115 | PM2.5 |
| 2021worst | 31 | 60 | 4 | 151 | PM2.5 |
| 2022cleanest | 31 | 52 | 0 | 100 | O3 |
| 2023 | 31 | 58 | 1 | 108 | PM2.5 |
| 2024 | 31 | 57 | 4 | 129 | O3 |
| 2025 | 31 | 54 | 3 | 136 | O3 |
What August air means in Philadelphia
A typical August day in Philadelphia is Moderate (median AQI 58): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 15 of August days (6.5%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
August's median AQI of 58 is in line with Philadelphia's whole-year median of 56, so this period is neither a clean nor a dirty stretch for the area. Nationally, the median August AQI across every EPA metro area (104,152 metro-days, 2019–2025) is 45, so Philadelphia runs above the national August norm; 6.5% of its August days topped AQI 100 versus 3.5% nationally (above average).
August is part of Philadelphia's summer season (June, July, August); the summer page pools all three months.
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Philadelphia
The latest EPA AirNow observation puts Philadelphia's AQI at 26 (O3). The figures above are multi-year month statistics, not today's reading.
View current Philadelphia air quality →Source: EPA Air Quality System (AQS) pre-generated Daily AQI by CBSA files — daily AQI by CBSA (Philadelphia-Camden-Wilmington, PA-NJ-DE-MD), 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.