Bad Air Days in Florence County, South Carolina: under 1 a Year
under 1 bad air days a year
Rare: among the cleanest-air counties EPA monitors. Ranked 911 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly particles: smoke and dust (100% 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 July and November. 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.
The worst days on file
The worst recent year was 2025, with 1 bad day on 361 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2025-11-06 | 108 | PM2.5 |
| 2023-07-18 | 104 | PM2.5 |
| 2024-03-14 | 99 | PM2.5 |
| 2025-02-25 | 99 | PM2.5 |
| 2023-06-29 | 98 | PM2.5 |
An ordinary day in Florence
Across 3,331 monitored days from 2016 to 2025, the air in Florence 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 42; one day in ten went above 58.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)100%3,331 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 361 | 235 | 125 | 1 | 0 | 44 | 108 |
| 2024 | 359 | 230 | 129 | 0 | 0 | 44 | 99 |
| 2023 | 364 | 191 | 172 | 1 | 0 | 49 | 104 |
| 2022 | 333 | 210 | 123 | 0 | 0 | 44 | 79 |
| 2021 | 337 | 251 | 86 | 0 | 0 | 39 | 86 |
| 2020 | 352 | 290 | 62 | 0 | 0 | 37 | 95 |
| 2019 | 361 | 243 | 118 | 0 | 0 | 41 | 73 |
| 2018 | 359 | 270 | 89 | 0 | 0 | 39 | 76 |
| 2017 | 273 | 197 | 76 | 0 | 0 | 38 | 71 |
| 2016 | 232 | 158 | 74 | 0 | 0 | 41 | 85 |
| 2015 | 168 | 88 | 80 | 0 | 0 | 49 | 77 |
| 2014 | 220 | 81 | 139 | 0 | 0 | 54 | 85 |
| 2013 | 219 | 94 | 125 | 0 | 0 | 52 | 77 |
| 2012 | 110 | 58 | 52 | 0 | 0 | 49 | 80 |
| 2011 | 116 | 50 | 66 | 0 | 0 | 54 | 89 |
| 2010 | 110 | 45 | 65 | 0 | 0 | 53 | 91 |
*2025 may be a partial year in EPA's file.
Nearby counties on file
- Cherokee Countythin data
- York County2/yr
- Spartanburg County2/yr
- Richland County1/yr
- Colleton County1/yr
- Greenville County1/yr
- Charleston Countyunder 1/yr
- Chesterfield 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.