Processed on 2024-03-04 13:59:53 PST.


Disclaimer: Data presented here come from a variety of sources and do not represent official EPA measurements. Please visit AirNow for official measurements.


Cumulative exposure to smoke is an important public health metric. This report summarizes the cumulative number of days air quality monitors in South Carolina spent in each AQI category during the the month of April.

The tables below include only permanent monitors measuring PM2.5 and show cumulative exposure under existing NAAQS (National Ambient Air Quality Standards) and under the 2024 revised standards for PM2.5.

In the tables and plots below, ‘Old’ designates cumulative days calculated using the 2023 PM2.5 NAAQS while ‘New’ is calculated using the 2024 revised PM2.5 NAAQS. The impact of the NAAQS revision is quite clear.

April in South Carolina

April 2014 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 127 61 3 0 0 0 26
New 83 105 3 0 0 0 26

April 2015 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 175 13 0 0 0 0 29
New 120 68 0 0 0 0 29

April 2016 – 15 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 140 32 0 0 0 0 45
New 96 76 0 0 0 0 45

April 2017 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 153 16 0 0 0 0 48
New 111 58 0 0 0 0 48

April 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 224 12 0 0 0 0 12
New 187 49 0 0 0 0 12

April 2019 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 199 6 0 0 0 0 74
New 158 47 0 0 0 0 74

April 2020 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 188 9 0 0 0 0 51
New 168 29 0 0 0 0 51

April 2021 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 172 33 0 0 0 0 12
New 128 77 0 0 0 0 12

April 2022 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 229 26 0 0 0 0 24
New 183 72 0 0 0 0 24

April 2023 – 11 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 258 42 0 0 0 0 10
New 185 115 0 0 0 0 10