San Francisco started yesterday on the mellow side, with cool, mostly clear skies and about 52°F at SFO this morning. Sunshine is expected to crank those numbers up into the mid-70s today, paired with a light west-northwest breeze and overnight lows in the low 50s. Layers are still your friend for waterfront errands and early commutes.
Long‑Duration Heat Building
Forecasters say a strong ridge of high pressure will settle over the region this weekend and stick around, setting up an unusually long heat spell next week. According to the National Weather Service San Francisco, the pattern could send temperatures well above normal and may even challenge March record highs.
Highs are expected to reach about 74°F today, and climb to around 78°F tomorrow. Next Monday and Tuesday could jump into the mid 80s (about 84–86°F), with daytime readings likely to linger in the low to mid 80s through Thursday and Friday, March 18–20, 2026. Nighttime lows should still slip into the upper 50s to low 60s near the water.
Afternoon Winds and Marine Advisories
West northwest breezes of 6–10 mph are expected across the city today, with stronger gusts along exposed shorelines and ridgelines. Offshore waters remain choppy, and Small Craft Advisories are in effect into Sunday and parts of Monday, so small boat operators and ferry riders should check carrier alerts before heading out.
Elevated Fire Risk
The warm, dry pattern, combined with occasional offshore gusts, will dry out fine fuels and raise the odds of grass fires next week. If you are camping, grilling, or working outdoors, skip open burning and report any smoke quickly.
Plan Ahead
Try to shift strenuous activity to the morning or late afternoon, keep water handy, and never leave children or pets in vehicles during the hottest hours. Older adults, very young children, and people with health conditions should plan to spend peak heat in cooled public spaces and keep an eye on local transit and ferry alerts if they have trips scheduled.
