Bad Air Days in Warren County, Pennsylvania
Not enough data
EPA monitors in Warren County ran on too few days between 2016 and 2025 to give a fair yearly count (about 41% of days covered). Neighbouring counties below are a better guide.
Is a purifier worth it here?
- EPA monitors here ran too few days to give a fair yearly count. Use AirNow for today's air.
The worst days on file
The worst recent year was 2025, with 3 bad days on 150 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2025-08-04 | 138 | PM2.5 |
| 2025-08-05 | 105 | PM2.5 |
| 2025-08-07 | 103 | PM2.5 |
| 2025-08-06 | 92 | PM2.5 |
| 2025-08-08 | 84 | PM2.5 |
The air on a normal day
Across 150 monitored days from 2025 to 2025, the air in Warren County rated Good on 79% of them, more often than the 72% typical of monitored counties, and Moderate on 19%. The median day sat at AQI 35; one day in ten went above 58.
The pollutant setting the AQI on an ordinary day here:
- ozone61%92 days
- fine particles (PM2.5)39%58 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 150 | 118 | 29 | 3 | 0 | 35 | 138 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- Allegheny County12/yr
- Philadelphia County9/yr
- Bucks County8/yr
- Lancaster County6/yr
- Berks County5/yr
- Delaware County4/yr
- Northampton County4/yr
- Montgomery County4/yr
How this is counted
A bad air day is a day the county's daily AQI from EPA AirData went above 100, the level where EPA tells children, older adults and people with asthma or heart disease to cut back outdoors. Monitors do not run every day, so yearly counts are scaled to 365 days. This is the record, not today's air: for that, check AirNow. More on the method in how the county numbers are made, on the AQI 100 line in what counts as a bad air day.