San Francisco started today with its familiar cool, partly cloudy vibe and temperatures in the low to mid 50s, but that classic sweater weather is on the clock. Temperatures are expected to climb into the upper 60s and low 70s over the weekend, then spike sharply early next week. The hottest stretch is forecast from Monday through Wednesday, and city officials are already warning of elevated heat and fire risks, while Small Craft Advisories remain in place offshore through Saturday.
Afternoon and Weekend Outlook
Today is expected to turn mostly sunny with a high near 70, setting up a sunnier Saturday with a high near 73. By next Sunday, many inland spots are forecast to warm into the upper 70s, while coastal neighborhoods and the immediate bayfront stay a few degrees cooler under the influence of the marine layer. Afternoon breezes should pick up near the water, and nighttime lows are projected to remain in the low to mid 50s.
Record Heat Possible Early Next Week
A sharp warmup from next Sunday into Monday is poised to kick off an early-season heat wave that could challenge March records. Forecasts call for Monday highs potentially reaching the mid 80s in parts of the city, with Tuesday and Wednesday bringing upper 80s to low 90s in inland areas as offshore winds develop. Small Craft Advisories are expected to continue for portions of the coast through Saturday, and the pattern raises HeatRisk and an elevated potential for grass fires, according to the National Weather Service.
How To Stay Cool
Health officials recommend limiting strenuous outdoor activity during the hottest hours, drinking plenty of water, and checking on neighbors who are elderly or have medical conditions. San Francisco maintains an extreme heat resources hub on SF.gov that includes an interactive map of cooling centers, pools, and public water stations, and residents are urged to sign up for AlertSF for official notices before heading out. Outdoor workers are advised to shift heavy tasks to early morning or evening when possible and follow employer heat safety guidance.
Transport And Boating Notes
Breezy afternoons near the water are expected through the weekend, along with pockets of morning fog that could reduce visibility around SFO and nearby terminals early in the day. Ferry and small boat operators should prepare for choppy seas in exposed waters and possible schedule impacts through Saturday. If you have outdoor plans, consider shifting activities to mornings or late evenings and keep an eye on operator notices and National Weather Service updates for changing conditions.
