Philadelphia Air Quality in March
Across 2019–2025, Philadelphia's March air quality had a median AQI of 53 (Moderate) over 217 monitored days in the Philadelphia-Camden-Wilmington, PA-NJ-DE-MD area. 0.0% of March days (0 of 217) reached Unhealthy for Sensitive Groups or worse, and fine particulate matter (PM2.5) set the daily AQI on 74.2% of days. The cleanest March on record here was 2025 (median AQI 48, 0 days above 100) and the worst was 2019 (median 56, 0 days above 100, peak AQI 81).
- Good: 36.9%
- Moderate: 63.1%
- Unhealthy for Sensitive Groups: 0.0%
- Unhealthy or worse: 0.0%
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 March?
Moderate on a typical day: median AQI 53 across 2019–2025, with 0.0% of March days above AQI 100. Fine particulate matter (PM2.5) is the main driver.
- ✓36.9% of March days were Good (AQI 0–50), 63.1% Moderate (51–100).
- ✓0 days of 217 reached AQI 101+; the March peak was 92.
- ✓Best March: 2025; worst March: 2019.
Frequently asked questions
What is the air quality like in Philadelphia in March?▾
Across 2019–2025, the median daily AQI in Philadelphia in March was 53 (Moderate). 36.9% of days were Good, 63.1% Moderate, and 0.0% reached Unhealthy for Sensitive Groups or worse, based on 217 monitored days in EPA's Air Quality System.
Is March a good time for outdoor exercise in Philadelphia?▾
A typical March day in Philadelphia is Moderate (median AQI 53): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of March days 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 March air quality problems?▾
Fine particulate matter (PM2.5) set the daily AQI on 74.2% of March days in Philadelphia. The highest March AQI recorded in 2019–2025 was 92 (Moderate), in 2019.
Philadelphia March air quality, year by year
Philadelphia March 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 |
|---|---|---|---|---|---|
| 2019worst | 31 | 56 | 0 | 81 | PM2.5 |
| 2020 | 31 | 55 | 0 | 74 | PM2.5 |
| 2021 | 31 | 52 | 0 | 88 | PM2.5 |
| 2022 | 31 | 55 | 0 | 77 | PM2.5 |
| 2023 | 31 | 53 | 0 | 92 | PM2.5 |
| 2024 | 31 | 52 | 0 | 84 | PM2.5 |
| 2025cleanest | 31 | 48 | 0 | 78 | O3 |
What March air means in Philadelphia
A typical March day in Philadelphia is Moderate (median AQI 53): outdoor exercise is acceptable for most people, but unusually sensitive individuals should watch for symptoms, and fewer than 1% of March days reached AQI 101+ — the level at which EPA advises people with asthma, children and older adults to shorten hard outdoor exertion.
March's median AQI of 53 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 March AQI across every EPA metro area (102,455 metro-days, 2019–2025) is 42, so Philadelphia runs above the national March norm; 0.0% of its March days topped AQI 100 versus 0.4% nationally (about the same).
March is part of Philadelphia's spring season (March, April, May); the spring 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.