New York, New York vs Philadelphia, Pennsylvania Air Quality
Side-by-side air quality comparison using 10 years of EPA monitoring data. New York, New York has the edge with an Air Quality Grade of B (70/100).
| Metric | New York, New York | Philadelphia, Pennsylvania |
|---|---|---|
| Air Quality Grade | B (70/100) | C (59/100) |
| Current Median AQI | 48 (Good) | 58 (Moderate) |
| 5-Year Average AQI | 44 | 52 |
| 10-Year Trend | ↓ Improving (-4) | ↓ Improving (-1) |
| Unhealthy Days/Year | 4 | 8 |
| Primary Pollutant | Fine Particulate Matter (PM2.5) | Fine Particulate Matter (PM2.5) |
Side-by-Side Analysis
New York, New York outperforms Philadelphia, Pennsylvania on overall air quality with a Grade B (70/100) versus C (59/100). New York, New York's 5-year median AQI of 44 sits in the "Good" range, while Philadelphia, Pennsylvania averages 52 ("Moderate") — a 8-point gap that shows up consistently in year-over-year readings, not just in a single year.
Both cities are on improving trajectories — New York, New York at roughly 1.2 AQI/yr cleaner and Philadelphia, Pennsylvania at 0.5 AQI/yr cleaner. That mirrors the broader U.S. pattern of falling pollution as cleaner vehicles, cleaner power generation, and tighter emissions standards take effect.
What's in the Air
Both cities share the same dominant pollutant: Fine Particulate Matter (PM2.5). These cities' dominant issue is fine particulate matter — typically driven by combustion (vehicles, wildfire smoke, industry, residential wood burning). PM2.5 is the air pollutant most strongly linked to long-term cardiovascular and respiratory disease because the particles penetrate the bloodstream.
Health Implications
Over a 5-year window, New York, New York averages roughly 4 unhealthy air days per year (AQI above 100, where sensitive groups should limit outdoor exertion) versus 8 for Philadelphia, Pennsylvania. The two cities offer comparable counts of unhealthy days, suggesting that day-to-day exposure planning would look similar for residents of either. For long-term residents, the cleaner-air city is associated with measurably better outcomes on respiratory disease, cardiovascular events, and life expectancy — Harvard cohort research consistently finds 0.5 to 1.0 years of additional life expectancy for each 10-µg/m³ reduction in long-term PM2.5 exposure.
Frequently Asked Questions
New York, New York has better air quality with a Grade B (70/100) compared to Philadelphia, Pennsylvania's Grade C (59/100). New York, New York has a current median AQI of 48 and is improving over the past decade.
New York, New York averages 4 unhealthy air days per year (5-year average), while Philadelphia, Pennsylvania averages 8. Unhealthy days are those when AQI exceeds 100 and sensitive groups should limit outdoor activity.
New York, New York's primary pollutant is Fine Particulate Matter (PM2.5), while Philadelphia, Pennsylvania's is Fine Particulate Matter (PM2.5). Both cities share the same dominant pollutant.
Source: EPA Outdoor Air Quality Data, 2026.
The side-by-side above pulls the EPA Air Quality System data data for both New York, New York and Philadelphia, Pennsylvania. What follows is the interpretation — which specific axes carry the most weight for New York, New York versus Philadelphia, Pennsylvania, and which differences are large enough to influence a real decision.
For households or analysts using this comparison as a decision input, the right framing is usually not "which is better" in aggregate but "which is better for the specific decision in front of you." EPA Air Quality System data captures the raw data; the framing depends on whether the question is investment, residency, planning, or research.