Bad Air Days in Douglas County, Kansas: 1 a Year
1 bad air day a year
Fewer bad air days than most monitored US counties. Ranked 624 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (0% 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 May. 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.
Better or worse than it was
In 2000 to 2009 this county averaged 14 bad days a year; in 2016 to 2025, 1. The air has improved. The worst recent year was 2025, with 1 bad day on 283 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2025-05-12 | 101 | Ozone |
| 2025-05-11 | 87 | Ozone |
| 2025-05-10 | 84 | Ozone |
| 2025-04-12 | 71 | Ozone |
| 2025-04-13 | 71 | Ozone |
The air on a normal day
Across 283 monitored days from 2025 to 2025, the air in Douglas County rated Good on 93% of them, more often than the 72% typical of monitored counties, and Moderate on 7%. The median day sat at AQI 37; one day in ten went above 49.
The pollutant setting the AQI on an ordinary day here:
- ozone100%283 days
Year by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 283 | 263 | 19 | 1 | 0 | 37 | 101 |
*2025 may be a partial year in EPA's file.
Elsewhere in Kansas
- Wyandotte County5/yr
- Shawnee County2/yr
- Sedgwick County2/yr
- Trego County2/yr
- Sumner County2/yr
- Johnson County2/yr
- Neosho County1/yr
- Leavenworth County1/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.