Temperatures around the Bay Area will spike starting Tuesday, with some areas nearing triple digits, forecasters said.
A high pressure system will bring moderate heat risk for some inland communities Tuesday through Friday, the National Weather Service said.
Wednesday and Thursday are forecast to be the warmest days, with high temperatures 5 to 15 degrees above average at areas away from the coast.
High temperatures in the 90s to near 100 are expected inland, and in the 80s near San Francisco Bay.
Friday will mark the beginning of cooler temperatures, the weather service said.
The warming trend prompted air district officials to call for a Spare the Air Alert on Tuesday and Wednesday.
High temperatures and light winds, combined with vehicle exhaust, will result in smog, the Bay Area Air Quality Management District said in an alert sent Monday.