A heat advisory that the National Weather Service issued remains in effect until 8 p.m. Thursday as temperatures climb to the 90s and 100s in parts of the Bay Area.
Temperatures across the interior of the region will range from 95 to 107 degrees, according to weather officials.
The heat advisory applies to North Bay and East Bay mountains and valleys, interior Monterey County, Southern Salinas Valley, Santa Clara Valley, and inland cities.
Air quality will be poor as a result of the high temperatures, according to the Bay Area Air Quality Management District, which has issued a 'Spare the Air' alert for Thursday.
Spare the Air alerts are issued when ozone pollution is forecast to reach unhealthy levels.