Bad Air Days in Prince George's County, Maryland: 5 a Year
5 bad air days a year
More bad air days than three quarters of monitored counties. Ranked 201 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (6% particle days).
The bad-air season here
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in July and June. Averaged over 2016 to 2025.
What actually helps here
- Ozone drives many bad days here. Purifiers and filters do not remove ozone, so do not buy one for that. Ozone peaks on hot afternoons: exercise outside in the morning.
The worst days on file
In 2000 to 2009 this county averaged 33 bad days a year; in 2016 to 2025, 5. The air has improved. The worst recent year was 2023, with 11 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2023-06-08 | 192 | PM2.5 |
| 2023-06-29 | 172 | PM2.5 |
| 2018-07-09 | 166 | Ozone |
| 2023-06-07 | 159 | PM2.5 |
| 2018-06-18 | 150 | Ozone |
An ordinary day in Prince George's
Across 3,653 monitored days from 2016 to 2025, the air in Prince George's County rated Good on 73% of them, close to the 72% typical of monitored counties, and Moderate on 25%. The median day sat at AQI 42; one day in ten went above 64.
The pollutant setting the AQI on an ordinary day here:
- ozone69%2,505 days
- fine particles (PM2.5)30%1,106 days
- nitrogen dioxide1%42 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 306 | 56 | 3 | 0 | 40 | 126 |
| 2024 | 366 | 280 | 83 | 3 | 0 | 39 | 129 |
| 2023 | 365 | 253 | 101 | 11 | 3 | 44 | 192 |
| 2022 | 365 | 313 | 51 | 1 | 0 | 39 | 101 |
| 2021 | 365 | 287 | 73 | 5 | 0 | 41 | 129 |
| 2020 | 366 | 314 | 51 | 1 | 0 | 39 | 105 |
| 2019 | 365 | 234 | 125 | 6 | 0 | 45 | 122 |
| 2018 | 365 | 248 | 109 | 8 | 1 | 42 | 166 |
| 2017 | 365 | 240 | 119 | 6 | 0 | 45 | 133 |
| 2016 | 366 | 199 | 158 | 9 | 0 | 48 | 129 |
| 2015 | 365 | 128 | 230 | 7 | 1 | 55 | 156 |
| 2014 | 365 | 160 | 201 | 4 | 0 | 52 | 119 |
| 2013 | 365 | 186 | 173 | 6 | 0 | 50 | 122 |
| 2012 | 366 | 142 | 201 | 23 | 6 | 54 | 197 |
| 2011 | 363 | 131 | 203 | 29 | 7 | 54 | 174 |
| 2010 | 362 | 133 | 194 | 35 | 6 | 56 | 172 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- Baltimore County8/yr
- Harford County7/yr
- Anne Arundel County5/yr
- Cecil County4/yr
- Baltimore City4/yr
- Kent County2/yr
- Frederick County2/yr
- Charles County2/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, and on why a purifier does not touch ozone in smoke vs ozone.