Processed on 2024-03-04 13:06:52 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 Illinois spent in each AQI category during the the month of October.

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.

October in Illinois

October 2014 – 11 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 270 32 0 0 0 0 50
New 213 89 0 0 0 0 50

October 2015 – 12 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 291 54 0 0 0 0 39
New 227 118 0 0 0 0 39

October 2016 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 279 18 0 0 0 0 87
New 211 86 0 0 0 0 87

October 2017 – 21 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 464 57 0 0 0 0 119
New 373 148 0 0 0 0 119

October 2018 – 40 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 479 58 0 0 0 0 103
New 381 156 0 0 0 0 103

October 2019 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 500 44 0 0 0 0 96
New 408 136 0 0 0 0 96

October 2020 – 43 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 596 61 0 0 0 0 47
New 490 167 0 0 0 0 47

October 2021 – 23 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 609 83 0 0 0 0 44
New 481 211 0 0 0 0 44

October 2022 – 24 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 565 128 0 0 0 0 43
New 391 302 0 0 0 0 43

October 2023 – 26 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 660 104 0 0 0 0 68
New 484 280 0 0 0 0 68