San Jose lies inland, ringed on three sides by mountains, and is drier and sunnier than coastal San Francisco. It averages about 298 days of sunshine and a mean temperature of 61.4 °F, from around 50 °F in December and January to around 70 °F in July and August. The record high is 109 °F, on September 6, 2022; the record low is 18 °F, on January 6, 1894.
The city has many microclimates. The Santa Cruz Mountains cast a rain shadow, so downtown gets the least rain in the city while South San Jose, ten miles away, gets more rain and wider swings of temperature. The 2020-21 rain year was the driest in 127 years of records. Snow almost never falls in the valley; the last time it stayed on the ground was February 5, 1976, though Mount Hamilton is sometimes white for a few days.