Bad Air Days in Jessamine County, Kentucky: under 1 a Year
under 1 bad air day a year
Rare: among the cleanest-air counties EPA monitors. Ranked 793 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (0% particle days).
When the bad days come in Jessamine
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in June and July and September. 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.
Better or worse than it was
In 2000 to 2009 this county averaged 16 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2023, with 2 bad days on 245 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2016-09-14 | 126 | Ozone |
| 2023-06-28 | 122 | Ozone |
| 2023-06-06 | 105 | Ozone |
| 2021-07-28 | 101 | Ozone |
| 2017-06-03 | 100 | Ozone |
The air on a normal day
Across 2,538 monitored days from 2016 to 2025, the air in Jessamine County rated Good on 87% of them, more often than the 72% typical of monitored counties, and Moderate on 12%. The median day sat at AQI 41; one day in ten went above 54.
The pollutant setting the AQI on an ordinary day here:
- ozone93%2,360 days
- fine particles (PM2.5)7%178 days
Year by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 363 | 285 | 78 | 0 | 0 | 41 | 100 |
| 2024 | 245 | 200 | 45 | 0 | 0 | 43 | 93 |
| 2023 | 245 | 211 | 32 | 2 | 0 | 43 | 122 |
| 2022 | 243 | 215 | 28 | 0 | 0 | 40 | 87 |
| 2021 | 227 | 211 | 15 | 1 | 0 | 38 | 101 |
| 2020 | 243 | 232 | 11 | 0 | 0 | 37 | 77 |
| 2019 | 245 | 221 | 24 | 0 | 0 | 43 | 67 |
| 2018 | 237 | 207 | 30 | 0 | 0 | 39 | 90 |
| 2017 | 245 | 226 | 19 | 0 | 0 | 40 | 100 |
| 2016 | 245 | 209 | 35 | 1 | 0 | 41 | 126 |
| 2015 | 244 | 213 | 30 | 1 | 0 | 40 | 105 |
| 2014 | 245 | 201 | 44 | 0 | 0 | 41 | 90 |
| 2013 | 238 | 220 | 18 | 0 | 0 | 40 | 77 |
| 2012 | 243 | 180 | 50 | 13 | 0 | 43 | 136 |
| 2011 | 245 | 185 | 56 | 4 | 0 | 44 | 140 |
| 2010 | 244 | 166 | 75 | 3 | 0 | 46 | 108 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- Jefferson County9/yr
- Oldham County3/yr
- Henderson County2/yr
- Campbell County2/yr
- Boone County2/yr
- Bullitt County2/yr
- McCracken County2/yr
- Daviess 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.