Philadelphia Air Quality in Summer
Across 2019–2025, Philadelphia's summer (June–August) air quality had a median AQI of 61 (Moderate) over 644 monitored days in the Philadelphia-Camden-Wilmington, PA-NJ-DE-MD area. 11.8% of summer days (76 of 644) reached Unhealthy for Sensitive Groups or worse, and ground-level ozone set the daily AQI on 50.5% of days. The cleanest summer on record here was 2020 (median AQI 58, 5 days above 100) and the worst was 2023 (median 66, 18 days above 100, peak AQI 331).
- Good: 21.4%
- Moderate: 66.8%
- Unhealthy for Sensitive Groups: 10.4%
- Unhealthy or worse: 1.4%
Reduce Indoor Ozone in Philadelphia
Today's main pollutant in Philadelphia is ground-level ozone (AQI 44). 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
As an Amazon Associate, we earn from qualifying purchases.
How is the air in Philadelphia in summer?
Moderate on a typical day: median AQI 61 across 2019–2025, with 11.8% of summer days above AQI 100. Ground-level ozone is the main driver.
- ✓21.4% of summer days were Good (AQI 0–50), 66.8% Moderate (51–100).
- ✓76 days of 644 reached AQI 101+; the summer peak was 331.
- ✓Cleanest month: August; worst month: June.
Frequently asked questions
What is the air quality like in Philadelphia in summer?▾
Across 2019–2025, the median daily AQI in Philadelphia in summer was 61 (Moderate). 21.4% of days were Good, 66.8% Moderate, and 11.8% reached Unhealthy for Sensitive Groups or worse, based on 644 monitored days in EPA's Air Quality System.
Is summer a good time for outdoor exercise in Philadelphia?▾
A typical summer day in Philadelphia is Moderate (median AQI 61): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 8 of summer days (11.8%) 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 summer air quality problems?▾
Ground-level ozone set the daily AQI on 50.5% of summer days in Philadelphia. The highest summer AQI recorded in 2019–2025 was 331 (Hazardous), in 2023.
Philadelphia summer air quality, year by year
Philadelphia summer 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 | 92 | 62 | 10 | 150 | O3 |
| 2020cleanest | 92 | 58 | 5 | 129 | PM2.5 |
| 2021 | 92 | 60 | 14 | 153 | PM2.5 |
| 2022 | 92 | 59 | 5 | 126 | O3 |
| 2023worst | 92 | 66 | 18 | 331 | PM2.5 |
| 2024 | 92 | 64 | 12 | 150 | O3 |
| 2025 | 92 | 59 | 12 | 161 | O3 |
What summer air means in Philadelphia
A typical summer day in Philadelphia is Moderate (median AQI 61): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and about 1 day in 8 of summer days (11.8%) reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
Summer's median AQI of 61 is above Philadelphia's whole-year median of 56, making it one of the area's dirtier periods. Nationally, the median Summer AQI across every EPA metro area (308,645 metro-days, 2019–2025) is 46, so Philadelphia runs above the national Summer norm; 11.8% of its Summer days topped AQI 100 versus 3.6% nationally (above average).
Within the season, August is the cleanest month (median AQI 58, 6.5% of days above 100) and June the worst (median 61, 15.2% above 100).
Activity-specific thresholds: running, cycling, kids' sports.
Right now in Philadelphia
The latest EPA AirNow observation puts Philadelphia's AQI at 44 (O3). The figures above are multi-year season 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.