Bad Air Days in Christian County, Kentucky: under 1 a Year
under 1 bad air day a year
Rare: among the cleanest-air counties EPA monitors. Ranked 795 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (40% 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 June and July. Averaged over 2016 to 2025.
What to buy, and what not to
- 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 Christian
In 2000 to 2009 this county averaged 27 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2023, with 5 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2023-07-16 | 117 | PM2.5 |
| 2023-06-05 | 115 | Ozone |
| 2023-06-28 | 104 | PM2.5 |
| 2023-06-06 | 101 | Ozone |
| 2023-06-10 | 101 | Ozone |
The air on a normal day
Across 3,260 monitored days from 2016 to 2025, the air in Christian County rated Good on 70% of them, close to the 72% typical of monitored counties, and Moderate on 30%. The median day sat at AQI 43; one day in ten went above 59.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)54%1,773 days
- ozone46%1,487 days
Christian County by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 364 | 266 | 98 | 0 | 0 | 41 | 87 |
| 2024 | 360 | 274 | 86 | 0 | 0 | 42 | 84 |
| 2023 | 365 | 213 | 147 | 5 | 0 | 47 | 117 |
| 2022 | 365 | 201 | 164 | 0 | 0 | 48 | 85 |
| 2021 | 365 | 190 | 175 | 0 | 0 | 49 | 99 |
| 2020 | 320 | 249 | 71 | 0 | 0 | 41 | 85 |
| 2019 | 278 | 228 | 50 | 0 | 0 | 40 | 80 |
| 2018 | 280 | 217 | 63 | 0 | 0 | 41 | 90 |
| 2017 | 280 | 230 | 50 | 0 | 0 | 41 | 71 |
| 2016 | 283 | 223 | 60 | 0 | 0 | 41 | 90 |
| 2015 | 270 | 196 | 74 | 0 | 0 | 44 | 87 |
| 2014 | 277 | 195 | 82 | 0 | 0 | 43 | 90 |
| 2013 | 279 | 189 | 89 | 1 | 0 | 44 | 101 |
| 2012 | 284 | 162 | 110 | 12 | 0 | 48 | 122 |
| 2011 | 279 | 150 | 127 | 2 | 0 | 49 | 108 |
| 2010 | 281 | 133 | 140 | 8 | 0 | 51 | 122 |
*2025 may be a partial year in EPA's file.
Kentucky compared
- 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.