Bad Air Days in Oxford County, Maine: under 1 a Year
under 1 bad air days a year
Rare: among the cleanest-air counties EPA monitors. Ranked 839 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly particles: smoke and dust (100% particle days).
When the bad days come in Oxford
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in July and August. Averaged over 2016 to 2025.
Is a purifier worth it here?
- Bad air days are rare here. A standard furnace filter is enough; no purifier needed for outdoor air.
- On the odd bad day, check AirNow and keep windows shut.
The record for Oxford
In 2000 to 2009 this county averaged 2 bad days a year; in 2016 to 2025, under 1. Not much has changed. The worst recent year was 2025, with 3 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2025-07-26 | 135 | PM2.5 |
| 2021-07-26 | 113 | PM2.5 |
| 2025-08-04 | 107 | PM2.5 |
| 2025-07-27 | 101 | PM2.5 |
| 2018-11-25 | 98 | PM2.5 |
The air on a normal day
Across 3,529 monitored days from 2016 to 2025, the air in Oxford County rated Good on 84% of them, more often than the 72% typical of monitored counties, and Moderate on 16%. The median day sat at AQI 36; one day in ten went above 54.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)56%1,974 days
- ozone44%1,555 days
Oxford County by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 277 | 85 | 3 | 0 | 38 | 135 |
| 2024 | 364 | 326 | 38 | 0 | 0 | 32 | 71 |
| 2023 | 356 | 288 | 68 | 0 | 0 | 38 | 83 |
| 2022 | 358 | 324 | 34 | 0 | 0 | 33 | 96 |
| 2021 | 360 | 308 | 51 | 1 | 0 | 35 | 113 |
| 2020 | 324 | 299 | 25 | 0 | 0 | 36 | 69 |
| 2019 | 334 | 305 | 29 | 0 | 0 | 33 | 72 |
| 2018 | 354 | 290 | 64 | 0 | 0 | 39 | 98 |
| 2017 | 351 | 260 | 91 | 0 | 0 | 40 | 87 |
| 2016 | 363 | 280 | 83 | 0 | 0 | 35 | 90 |
| 2015 | 340 | 249 | 91 | 0 | 0 | 39 | 90 |
| 2014 | 248 | 237 | 11 | 0 | 0 | 31 | 90 |
| 2013 | 204 | 200 | 4 | 0 | 0 | 30 | 87 |
| 2012 | 213 | 209 | 4 | 0 | 0 | 31 | 87 |
| 2011 | 199 | 196 | 3 | 0 | 0 | 31 | 71 |
| 2010 | 230 | 229 | 1 | 0 | 0 | 34 | 54 |
*2025 may be a partial year in EPA's file.
Maine compared
- York County2/yr
- Hancock County2/yr
- Cumberland County2/yr
- Aroostook County2/yr
- Knox County1/yr
- Penobscot Countyunder 1/yr
- Sagadahoc Countyunder 1/yr
- Washington Countyunder 1/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.