Processed on 2024-03-04 12:49:09 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 California spent in each AQI category during the the month of February.

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.

February in California

February 2014 – 116 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1399 250 19 1 0 0 39
New 1111 538 18 2 0 0 39

February 2015 – 136 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1204 500 19 0 0 0 97
New 922 780 21 0 0 0 97

February 2016 – 264 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1556 420 19 0 0 0 93
New 1262 713 20 0 0 0 93

February 2017 – 165 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2176 341 14 1 0 0 100
New 1882 632 17 1 0 0 100

February 2018 – 289 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1854 529 29 0 0 0 136
New 1488 892 32 0 0 0 136

February 2019 – 166 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2431 157 3 0 0 0 125
New 2264 324 3 0 0 0 125

February 2020 – 362 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2115 593 5 0 0 0 100
New 1642 1065 5 1 0 0 100

February 2021 – 220 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2478 459 18 0 0 0 153
New 2121 814 20 0 0 0 153

February 2022 – 237 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2441 811 34 3 0 0 155
New 2015 1236 35 3 0 0 155

February 2023 – 437 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2800 527 6 2 0 0 193
New 2392 934 7 2 0 0 193