San Francisco experienced a record-breaking heat wave on March 20, 2026, with temperatures soaring to 90°F (32°C), the highest ever recorded in March. This unprecedented heat, measured at the downtown weather station on Mint Hill near Duboce Park, surpassed the previous record of 87°F (31°C) set in 2005. The entire Bay Area is affected by this heat wave, with temperatures ranging from the mid-80s to the low 90s, significantly above the typical seasonal averages.