Bad Air Days in Mecklenburg County, North Carolina: 4 a Year
4 bad air days a year
About the middle of monitored US counties. Ranked 270 of 996 monitored counties, where 1 is worst.
What makes them bad: mostly ozone: summer smog (12% 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 June and May and August and September. Averaged over 2016 to 2025.
Is a purifier worth it here?
- Ozone drives many bad days here. Purifiers and filters do not remove ozone, so do not buy one for that. Ozone peaks on hot afternoons: exercise outside in the morning.
Better or worse than it was
In 2000 to 2009 this county averaged 41 bad days a year; in 2016 to 2025, 4. The air has improved. The worst recent year was 2019, with 10 bad days on 365 monitored days.
| Date | AQI | Main pollutant |
|---|---|---|
| 2024-08-27 | 156 | Ozone |
| 2016-11-16 | 155 | PM2.5 |
| 2023-07-18 | 150 | Ozone |
| 2019-09-11 | 136 | Ozone |
| 2019-09-09 | 129 | Ozone |
An ordinary day in Mecklenburg
Across 3,648 monitored days from 2016 to 2025, the air in Mecklenburg County rated Good on 49% of them, less often than the 72% typical of monitored counties, and Moderate on 50%. The median day sat at AQI 50; one day in ten went above 68.
The pollutant setting the AQI on an ordinary day here:
- fine particles (PM2.5)64%2,337 days
- ozone35%1,295 days
Every recent year on file
| Year | Days monitored | Good | Moderate | Over 100 | Over 150 | Median AQI | Highest AQI |
|---|---|---|---|---|---|---|---|
| 2025* | 365 | 176 | 189 | 0 | 0 | 51 | 97 |
| 2024 | 366 | 169 | 193 | 4 | 1 | 51 | 156 |
| 2023 | 365 | 174 | 185 | 6 | 0 | 51 | 150 |
| 2022 | 365 | 190 | 173 | 2 | 0 | 50 | 119 |
| 2021 | 365 | 188 | 175 | 2 | 0 | 49 | 128 |
| 2020 | 366 | 213 | 151 | 2 | 0 | 46 | 112 |
| 2019 | 365 | 161 | 194 | 10 | 0 | 52 | 136 |
| 2018 | 360 | 173 | 182 | 5 | 0 | 51 | 108 |
| 2017 | 365 | 148 | 214 | 3 | 0 | 53 | 115 |
| 2016 | 366 | 185 | 174 | 7 | 1 | 50 | 155 |
| 2015 | 365 | 173 | 183 | 9 | 0 | 52 | 129 |
| 2014 | 365 | 155 | 208 | 2 | 0 | 53 | 105 |
| 2013 | 365 | 188 | 175 | 2 | 0 | 49 | 101 |
| 2012 | 366 | 128 | 218 | 20 | 4 | 54 | 166 |
| 2011 | 365 | 104 | 229 | 32 | 8 | 57 | 169 |
| 2010 | 365 | 94 | 247 | 24 | 4 | 59 | 177 |
*2025 may be a partial year in EPA's file.
Elsewhere in North Carolina
- Jackson Countythin data
- Forsyth County2/yr
- Union County2/yr
- Swain County2/yr
- Haywood County2/yr
- Graham County1/yr
- Guilford County1/yr
- Wake 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.