Update, 3:15 p.m. Thursday: It's another day of record-breaking warmth in the Bay Area. The National Weather Service says the temperature at San Francisco International Airport hit 71 degrees earlier this afternoon, erasing the record 69 set in 1991. "Downtown" San Francisco — readings are taken at Mission Dolores — tied a record of 71, also set in 1991. Salinas tied its Jan. 16 high of 84, a mark recorded in 2009.
Original post (Wednesday): It wasn't just hot in Northern California Wednesday -- it was absolutely historic. Temperatures for Jan. 15 broke records all over the place, including San Francisco International Airport, where the 73-degree high set the station's all-time record for all of January, toppling the former high of 69 from 1974.
New marks were reached in 10 locations, and there was a tie in Mountain View with 72 degrees equaling a high from five years ago.
In downtown Oakland, it was 76 degrees, compared with 75 in 2009. Kentfield's 68-degree high edged out a 67-degree record that goes back to 1945. In Santa Cruz, it wasn't even close, peaking at 82 degrees, well ahead of the 75-degree high from 2009, a year when many highs for the day were established. Napa's 72-degree mark beat out the 70-degree high of 1966. And in Monterey it was 82, compared with 76 in 2009.
For more weather tidbits, check out the National Weather Service's Bay Area home page. The NWS reported that offshore winds pushed temperatures into the low 80s in Big Sur. A tenacious ridge of high pressure, which is responsible for the atypically high temperatures, makes it likely that afternoon temperatures will remain 15 to 20 degrees above seasonal averages for the rest of the workweek.