High temperatures, low humidity and offshore winds have prompted a red flag fire danger warning for the North and East Bay hills and the Diablo Range from Monday night through early Wednesday, the National Weather Service said.
The red flag warning replaces a fire weather watch advisory posted earlier Sunday.
Increasing offshore flow and poor overnight humidity recoveries were cited by the NWS, which is predicting very warm to hot temperatures Tuesday and Wednesday, along with gusty winds.
"Some minor coastal cooling is possible on Wednesday as onshore flow returns, although temperatures are forecast to remain warm," the agency said. "High temperatures on Tuesday and Wednesday are less certain and could trend warmer if offshore flow is strong."
Most areas around the region should have good air quality Monday through Wednesday, according to the Bay Area Air Quality Management District, with exceptions for the Santa Clara Valley and Eastern Zone of the Bay Area, where moderate air quality is forecast.