A thick pall of smoke continued to hang over much of Northern California on Tuesday as scores of lightning-sparked wildfires marched across 76,000 acres.
Air quality officials warned residents to stay indoors as the smoke from fires from Monterey County to the Oregon border obscured the sun.. Regulators said it was the worst air to hit the region in years.
Air quality is considered satisfactory when the Air Quality Index is below 100. In Butte County, smoke from nearby fires sent the index rocketing toward 205, surpassing the threshold for “very unhealthy” air. The index topped out at 210 in some parts of Sacramento County, and officials issued warnings to curtail outdoor activities even after it slipped lower late Tuesday. Further south in San Joaquin County, the smoky air hit 155 on the index. Even normally breezy San Francisco drooped for a second day under a haze spread by smoldering wildfires in Napa and Fairfield, and authorities issued a smoke advisory there.
Despite the eerie conditions, firefighters continued to make headway against the fires, which began Saturday when a rare onslaught of dry lightning hit scattered spots all over Northern California, igniting more than 800 blazes.
Most of the fires were being fought away from populated areas, but a blaze near Big Sur destroyed or damaged 16 homes and two adjacent structures. The 8,500-acre fire is one of two bedeviling the Los Padres National Forest. A wildfire that started earlier this month has charred about 60,000 acres.
Firefighters were making progress against fires in Napa and Shasta counties and those in Santa Cruz and San Benito counties have been contained.