Bad Air Days in Hancock County, Mississippi: under 1 a Year
under 1 bad air days a year
Rare: among the cleanest-air counties EPA monitors. Ranked 914 of 996 monitored counties, where 1 is worst.
What makes them bad: a mix of particles and ozone (50% particle days).
When the bad days come in Hancock
- J
- F
- M
- A
- M
- J
- J
- A
- S
- O
- N
- D
Most bad days here fall in March and August. Averaged over 2016 to 2025.
What actually helps 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 Hancock
In 2000 to 2009 this county averaged 17 bad days a year; in 2016 to 2025, under 1. The air has improved. The worst recent year was 2018, with 1 bad day on 363 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2023-08-17 | 112 | Ozone |
| 2018-03-21 | 102 | PM2.5 |
| 2018-05-17 | 100 | Ozone |
| 2023-08-02 | 100 | Ozone |
| 2023-08-18 | 100 | Ozone |
Most days, not the worst ones
Across 3,439 monitored days from 2016 to 2025, the air in Hancock County rated Good on 68% of them, less often than the 72% typical of monitored counties, and Moderate on 32%. The median day sat at AQI 44; one day in ten went above 59.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)66%2,262 days
- ozone34%1,177 days
Hancock County by year
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 256 | 109 | 0 | 0 | 43 | 84 |
| 2024 | 357 | 245 | 112 | 0 | 0 | 43 | 87 |
| 2023 | 364 | 188 | 175 | 1 | 0 | 50 | 112 |
| 2022 | 359 | 238 | 121 | 0 | 0 | 44 | 89 |
| 2021 | 360 | 225 | 135 | 0 | 0 | 45 | 97 |
| 2020 | 351 | 217 | 134 | 0 | 0 | 45 | 90 |
| 2019 | 365 | 263 | 102 | 0 | 0 | 43 | 80 |
| 2018 | 363 | 257 | 105 | 1 | 0 | 41 | 102 |
| 2017 | 278 | 225 | 53 | 0 | 0 | 40 | 77 |
| 2016 | 277 | 234 | 43 | 0 | 0 | 40 | 90 |
| 2015 | 276 | 212 | 64 | 0 | 0 | 38 | 85 |
| 2014 | 243 | 218 | 23 | 2 | 0 | 37 | 112 |
| 2013 | 241 | 218 | 23 | 0 | 0 | 38 | 87 |
| 2012 | 228 | 197 | 29 | 2 | 0 | 38 | 108 |
| 2011 | 280 | 195 | 83 | 2 | 0 | 44 | 119 |
| 2010 | 285 | 190 | 94 | 1 | 0 | 44 | 108 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- DeSoto County2/yr
- Harrison County1/yr
- Jackson Countyunder 1/yr
- Hinds Countyunder 1/yr
- Bolivar Countyunder 1/yr
- Forrest Countyunder 1/yr
- Lee Countyunder 1/yr
- Yalobusha 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, and on why a purifier does not touch ozone in smoke vs ozone.