Processed on 2024-03-04 14:00:02 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 May.

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.

May in South Carolina

May 2014 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 114 62 0 0 0 0 48
New 58 118 0 0 0 0 48

May 2015 – 7 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 176 36 0 0 0 0 12
New 112 100 0 0 0 0 12

May 2016 – 15 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 149 44 0 0 0 0 31
New 115 78 0 0 0 0 31

May 2017 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 160 34 0 0 0 0 30
New 121 73 0 0 0 0 30

May 2018 – 19 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 209 30 0 0 0 0 49
New 177 62 0 0 0 0 49

May 2019 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 189 41 0 0 0 0 26
New 132 98 0 0 0 0 26

May 2020 – 18 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 188 2 0 0 0 0 34
New 165 25 0 0 0 0 34

May 2021 – 9 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 158 43 0 0 0 0 23
New 121 80 0 0 0 0 23

May 2022 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 225 29 0 0 0 0 34
New 158 96 0 0 0 0 34

May 2023 – 11 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 242 65 0 0 0 0 13
New 170 137 0 0 0 0 13