Sweltering temps prompt heat advisories in the Bay Area

Warm to hot Tuesday

Tuesday will be the hottest day of the week. Highs should range from the low 80s to 102 well inland. A Spare the Air Alert has been issued for the Bay Area. A cooler system will approach the Bay Area Tuesday night. Shower and thunderstorm chances will be increasing by Wednesday. Update: The National Weather Service issued a Heat Advisory for parts of the Bay Area (Tuesday: 11 am to 7 pm). The advisory will be in effect for San Francisco, the Peninsula, South Bay, and the East Bay.

OAKLAND, Calif. - The National Weather Service forecast for the greater San Francisco Bay Area for Tuesday calls for warm conditions with mostly clear and sunny skies during the day, while coastal areas have low chances of thunderstorms at night.

Daytime highs will be mostly in the low 70s to mid 80s on the coast, in the mid 80 to upper 90s around the bay, and in the upper 90s to low 100s inland. Overnight lows will be mostly in the low to mid 60s. 

Forecasters say moderate heat risk will be widespread across the Bay Area on Tuesday, with some pockets of major heat risk. A Heat Advisory is in effect for the East Bay, the San Francisco Bay shoreline, the Santa Clara Valley, and the city of San Francisco until 7 p.m.

According to the NWS, the heat will vary by location in San Francisco. The eastern half of the city may warm into the mid to upper 80s, while the western half is expected to stay mostly in the 70s.

After these above-normal temperatures, rain chances are expected to increase Tuesday night across much of the Central Coast. The rain will then spread north during the day on Wednesday. Forecasters say that from late Wednesday morning through early evening, some areas that get showers may also see isolated thunderstorms.

According to the NWS, the rain will move east of the Bay Area by Thursday morning. Skies will then gradually clear on Thursday afternoon, especially away from the coast.