Processed on 2024-03-04 12:57:10 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 Delaware spent in each AQI category during the the month of December.

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.

December in Delaware

December 2014 – 3 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 58 34 1 0 0 0 0
New 40 52 1 0 0 0 0

December 2015 – 3 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 22 9 0 0 0 0 0
New 21 10 0 0 0 0 0

December 2016 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 78 15 0 0 0 0 0
New 59 34 0 0 0 0 0

December 2017 – 3 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 69 19 0 0 0 0 5
New 52 36 0 0 0 0 5

December 2018 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 108 39 0 0 0 0 8
New 80 67 0 0 0 0 8

December 2019 – 5 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 115 40 0 0 0 0 0
New 83 71 1 0 0 0 0

December 2020 – 10 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 111 34 0 0 0 0 10
New 93 52 0 0 0 0 10

December 2021 – 5 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 107 45 0 0 0 0 3
New 62 90 0 0 0 0 3

December 2022 – 6 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 141 22 0 0 0 0 23
New 99 64 0 0 0 0 23

December 2023 – 8 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 171 35 0 0 0 0 4
New 142 64 0 0 0 0 4