Last week, San Francisco experienced its hottest week in 85 years, with several cities in the Bay Area breaking century-old temperature records. According to the San Francisco Chronicle, from September 30 to October 6, the city recorded an average daily high of 90.3 degrees Fahrenheit, which is an astonishing 20 degrees above the norm. This marks the warmest week for San Francisco since 1939 and the third warmest since records began in September 1874, falling just short of the previous record of 93 degrees set in September 1939.
Interestingly, a weather station operated by Pacific Gas and Electric (PG&E), located just three blocks from Ocean Beach, recorded a much cooler average daily high of 78 degrees in the coastal area of San Francisco. However, the average nightly low temperature climbed to 69 degrees, making this week the hottest on record for October nights.
Several cities around the Bay also saw unprecedented temperatures last week. In San Jose, the average daily high hit 100.1 degrees, marking the hottest week for the city since July 1905. On October 2, temperatures soared to 106 degrees, the highest daily temperature recorded since 1980 and 2012. San Rafael reported a daily average peak of 102.7 degrees, surpassing the old record set in 1894, with a staggering high of 107 degrees on October 6.
Additionally, towns like Santa Rosa, Kentfield, and Napa recorded daily highs of 102 degrees on October 6—a record not seen since 1930.
As climate change, primarily driven by human activity, continues to warm our planet, the Environmental Protection Agency (EPA) has highlighted that average autumn temperatures in California have risen by approximately 3.1 degrees since 1896. This trend indicates that heatwaves are becoming more intense, frequent, and prolonged.
Meteorologist Nicole Sarment attributes the soaring temperatures last week to an unusually warm air mass and a lack of the cool maritime breezes that usually temper temperatures in coastal cities.
Looking ahead, the National Weather Service forecasts that by October 8, temperatures across the Bay Area are expected to drop below the 100-degree mark, though they will likely remain above normal for this time of year.
