A brief heat wave that will again bake parts of the Bay Area and smoke from the Flat Fire burning in southern Oregon have extended a Spare the Air alert through Saturday, officials said.
The Bay Area Air Quality Management District announced its decision at noon Friday, saying smog in the region is expected to be unhealthy. The air district urged residents to stay inside and avoid using vehicles.
The air was expected to be at its dirtiest Saturday, a day after temperatures were expected to spike, according to the National Weather Service. Brentwood (107 degrees) and Walnut Creek (101) were expected to be the two hottest spots in Contra Costa County on Friday; Livermore (103) was expected to lead Alameda County; and Morgan Hill (101) was forecasted to be the hottest spot in Santa Clara County.
A heat advisory was in effect in those areas through 11 p.m. Saturday.
Milder temperatures remained in areas closer to the bay, with the thermometer on Friday likely to reach 90 degrees in San Jose; 88 in Richmond; 80 in San Mateo; 79 in Oakland and 72 in San Francisco.
Air quality throughout the region was mostly moderately healthy Friday, meaning the particulate matter in the air was between 51-100. On Saturday, some areas of the region were expected to reach a reading of at least 101, meaning the air is unhealthy to those with breathing issues.
The air district has issued four Spare the Air alerts since July 13 and six in 2023.
The region is expected to begin cooling down on Sunday. Weather service forecasters said a trough of low pressure is expected to bring relief to some of the smoky air in Oregon. The Flat Fire has burned more than 15,000 acres.