Bad Air Days in Sublette County, Wyoming: 5 a Year
5 bad air days a year
More bad air days than three quarters of monitored counties. Ranked 209 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (18% particle days).
Which months to watch
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in March and July and August. Averaged over 2016 to 2025.
What to buy, and what not to
- 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 7 bad days a year; in 2016 to 2025, 5. Not much has changed. The worst recent year was 2019, with 11 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2019-03-21 | 200 | Ozone |
| 2019-03-20 | 187 | Ozone |
| 2019-03-10 | 164 | Ozone |
| 2025-08-23 | 164 | PM2.5 |
| 2025-08-26 | 157 | PM2.5 |
An ordinary day in Sublette
Across 3,653 monitored days from 2016 to 2025, the air in Sublette County rated Good on 71% of them, close to the 72% typical of monitored counties, and Moderate on 28%. The median day sat at AQI 46; one day in ten went above 69.
The pollutant setting the AQI on an ordinary day here:
- ozone95%3,463 days
- fine particles (PM2.5)5%189 days
Sublette County by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 256 | 104 | 5 | 3 | 47 | 164 |
| 2024 | 366 | 244 | 115 | 7 | 0 | 46 | 115 |
| 2023 | 365 | 237 | 122 | 6 | 0 | 47 | 122 |
| 2022 | 365 | 301 | 63 | 1 | 0 | 45 | 105 |
| 2021 | 365 | 253 | 105 | 7 | 0 | 46 | 133 |
| 2020 | 366 | 289 | 72 | 5 | 1 | 45 | 151 |
| 2019 | 365 | 265 | 89 | 11 | 3 | 46 | 200 |
| 2018 | 365 | 230 | 135 | 0 | 0 | 47 | 97 |
| 2017 | 365 | 220 | 137 | 8 | 0 | 48 | 150 |
| 2016 | 366 | 287 | 78 | 1 | 0 | 45 | 102 |
| 2015 | 365 | 288 | 76 | 1 | 0 | 45 | 101 |
| 2014 | 365 | 272 | 93 | 0 | 0 | 46 | 100 |
| 2013 | 365 | 273 | 92 | 0 | 0 | 46 | 100 |
| 2012 | 366 | 190 | 161 | 15 | 6 | 50 | 219 |
| 2011 | 365 | 194 | 154 | 17 | 5 | 50 | 219 |
| 2010 | 365 | 233 | 130 | 2 | 0 | 48 | 112 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- Platte County9/yr
- Sweetwater County7/yr
- Albany County6/yr
- Campbell County5/yr
- Sheridan County3/yr
- Laramie County3/yr
- Teton County3/yr
- Fremont 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.