Air Quality Impacts during the 2015 Rough Fire in Areas Surrounding the Sierra Nevada, California

The Rough Fire started on 31 July 2015 from a lightning strike, spread to over 61,000 ha and burned parts of the Sierra and Sequoia National Forests and the Sequoia & Kings Canyon National Parks, in California. Health advisories for smoke were issued in rural areas around the fire and in urban areas of the Central Valley. PM2.5 concentrations in rural and urban areas were used to assess the air quality impacts from the fire. Before the Rough Fire, 24-h PM2.5 concentrations for all sites ranged from 1 µg m−3o 50 µgm−3. During the wildfire, the 24-h PM2.5 concentrations ranged from 2 µgm−3 to 545 µgm−3, reaching hazardous levels of the federal Air Quality Index (AQI). The results indicate that the largest PM2.5 smoke impacts occurred at locations closer to and downwind of the fire in mountain communities of the Sierra Nevada, while the smoke impacts were lower in the urban areas.