San Francisco Air Pollution in 2020 and 2022

Smoky air from wildfires can have dangerous levels of the pollutant PM 2.5, or fine particulate matter. In 2022, no days exceeded the federal safety standard.

Average PM 2.5 levels above 35 ug/m^3 exceed the federal safety standard. Chart: Liz Lindqwister Source: U.S. Environmental Protection Agency
The San Francisco Standard