Processed on 2024-03-04 12:50:59 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 November.

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.

November in California

November 2014 – 116 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1302 529 35 13 0 0 136
New 1014 814 37 14 0 0 136

November 2015 – 136 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1506 465 24 7 0 0 168
New 1271 700 24 6 1 0 168

November 2016 – 264 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1918 578 43 8 0 0 305
New 1519 976 44 8 0 0 305

November 2017 – 165 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1990 663 38 2 0 0 221
New 1565 1084 41 3 0 0 221

November 2018 – 289 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1600 659 150 325 48 9 247
New 1300 952 154 298 72 15 247

November 2019 – 166 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1951 829 10 0 0 0 217
New 1477 1303 10 0 0 0 217

November 2020 – 362 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2115 887 47 2 0 0 235
New 1612 1389 48 2 0 0 235

November 2021 – 220 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2095 1106 83 1 0 0 311
New 1641 1555 88 1 0 0 311

November 2022 – 237 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2674 792 65 3 0 0 310
New 2193 1273 65 3 0 0 310

November 2023 – 437 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2868 894 10 3 0 0 317
New 2311 1449 12 3 0 0 317