Processed on 2024-03-04 12:49:57 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 June.

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.

June in California

June 2014 – 116 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1303 390 2 2 0 0 163
New 905 788 2 2 0 0 163

June 2015 – 136 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1598 374 1 0 0 0 197
New 1191 781 1 0 0 0 197

June 2016 – 264 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1690 383 0 0 0 0 128
New 1259 813 1 0 0 0 128

June 2017 – 165 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 1929 523 1 0 0 0 399
New 1472 980 1 0 0 0 399

June 2018 – 289 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2062 611 5 4 1 0 293
New 1404 1269 5 2 3 0 293

June 2019 – 166 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2401 306 0 0 0 0 424
New 1920 787 0 0 0 0 424

June 2020 – 362 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2627 274 0 0 0 0 168
New 2229 672 0 0 0 0 168

June 2021 – 220 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 2627 370 1 0 0 0 474
New 2152 844 2 0 0 0 474

June 2022 – 237 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 3018 441 2 0 0 0 445
New 2545 914 2 0 0 0 445

June 2023 – 437 permanent monitors

Good Moderate USG Unhealthy Very Unhealthy Hazardous Missing
Old 3365 258 0 0 0 0 283
New 2774 849 0 0 0 0 283