San Francisco Air Quality Fall 2020

For weeks, millions of Californians were smothered by smoke from a record explosion of wildfires burning through grass, shrubs, conifer forests, homes and businesses. Many cloistered themselves indoors as pollution spiked to “hazardous” levels, or worse. Smoke transported health dangers to nearly every corner of the state. Even as air quality begins to improve, many remain worried about the long-term health impacts on residents.

This quilt was made as the fires raged from September 3 through the first rains of the season on November 8, 2020. Each 4 inch square was modeled from screen shots captured on PurpleAir.com of the outdoor Air Quality Index of San Francisco. The higher the AQI value, the greater the level of air pollution and the greater the health concern. Air quality ranged from purple/red (hazardous/unhealthy), to orange/yellow (unhealthy for sensitive groups/moderate) to green (good/satisfactory.) San Francisco’s microclimates and hilly terrain causes much variety in the small 7x7-mile city, as indicated by the varied confetti and bar colors at any one point in time.

Experts say these kinds of wildfires will become routine if we do not take significant action to adapt to climate change and reduce greenhouse-gas emissions.