Monday will be a transition day, as morning fog gives way to afternoon clearing. High temperatures are expected to be near to slightly below normal, in the 60s at the coast, 70s along the bay shoreline and upper 70s to mid-80s inland.<\/p>\n
Above-normal temperatures will kick off Tuesday, with no major sign for when the warm weather will end. It’s possible San Francisco’s official weather station<\/a> hits 70 degrees every day for at least a week straight. The only other time that happened this year was during a historic March heat wave<\/a>.<\/p>\n On Tuesday, northerly winds will usher warm, dry air into the Bay Area. That will likely keep fog away from the region and allow San Francisco temperatures to climb into the 70s to low 80s, with mid-80s in Oakland and 90s in the inland valleys. Similar conditions are in store Wednesday, with temperatures up to 95 possible in the Tri- and Diablo valleys.<\/p>\n It’s unclear exactly how temperatures will trend Thursday into the weekend for the Hardly Strictly Bluegrass festival in Golden Gate Park, but the official National Weather Service forecast still calls for 70s through Sunday.<\/p>\n Most weather models predict a high-pressure system centered over the Western U.S. this weekend will keep temperatures above normal. There is a slight chance temperatures trend lower, but most data indicates an extended spell of warm weather in the Bay Area from late September through early October. (Baron\/Lynx)<\/p>\n The first full week of October is trending even warmer. Typhoons near Japan are expected to energize the jet stream over the Pacific Ocean. The wavy storm track will probably pump up a warm high-pressure system over the Western U.S. The Climate Prediction Center’s long-range outlook indicates likely above-normal temperatures and odds leaning toward below-normal precipitation in the Bay Area through Oct. 11.<\/p>\n October is also the most common month of the year for hot, dry winds that blow toward San Francisco Bay from the vicinity of Mount Diablo, aptly named Diablo winds<\/a>. At least a few rounds of these arid breezes are expected throughout the month, and will likely make for some warm days in San Francisco.<\/p>\n Monday breakdown<\/p>\n San Francisco: Patchy fog in the morning is expected to clear for a sunny afternoon. Highs will be in the low to mid-60s west of Twin Peaks and the mid- to upper 60s to the east. Gusts up to 25 mph are possible in the afternoon and evening. Minimal fog is expected overnight, with lows in the mid- to upper 50s.<\/p>\n North Bay: Abundant sunshine is expected across the North Bay. High temperatures will return to near to slightly above normal, in the low to mid-80s across Wine Country. Vallejo, Tiburon and Mill Valley should reach the 70s. Coastal areas will be in the 60s. Skies will be clear overnight as northerly gusts up to 20 mph blow dry air into the region. Even stronger gusts are expected atop hills. Lows will be in the 50s in the valleys and 60s in the hills.<\/p>\n East Bay: Sunshine should prevail quickly, allowing afternoon high temperatures to return to near normal, in the upper 60s to mid-70s along the bay shoreline and upper 70s to mid-80s in the interior valleys. Cool breezes off San Francisco Bay in the afternoon may gust up to 20 mph. Winds will turn out of the north overnight, ushering in dry air that prevents fog from forming. Lows will be in the 50s in the valleys and 60s in the hills.<\/p>\n Pacific Coast and Peninsula: Morning clouds will give way to afternoon sunshine. Highs will be in the low to mid-60s at the coast. The Highway 101 corridor will see temperatures range from the low 70s near San Francisco International Airport to the upper 70s in Redwood City. Gusts could occasionally exceed 25 mph in the afternoon. Lows will be in the 50s under mainly clear skies.<\/p>\n South Bay and Santa Cruz: Winds off the bay will keep the Santa Clara Valley relatively cooler than other parts of the Bay Area, as highs are capped in the 70s, a few degrees below late September normals. These winds should keep the fog away from Santa Cruz, though, as temperatures soar to the upper 70s to low 80s there. Minimal fog is expected overnight, with lows in the 50s in the valleys and 60s in the higher elevations.<\/p>\n Subscribe<\/p>\n There’s more to San Francisco with the Chronicle. Subscribe today for just 25\u00a2.<\/a><\/p>\n![\"Most](\"https:\/\/www.newsbeep.com\/us-ca\/wp-content\/uploads\/2026\/09\/https:\/\/media.zenfs.com\/en\/san_francisco_chronicle_hearst_178\/90189da8176fd2ad1df45574907e361b.jpg\"\/)
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