Milpitas enjoys a warm-summer Mediterranean climate (Köppen climate classification Csb/Csa), characterized by warm, completely dry summers and mild, moderately wet winters. Because it is slightly inland and shielded by the Santa Cruz Mountains to the west, it tends to be warmer in the summer than cities located directly on the San Francisco Peninsula.
Average summer highs typically range from 80°F to 85°F (27°C - 29°C), though occasional heat waves can push temperatures above 95°F. Winter temperatures are mild, with average highs in the upper 50s to low 60s Fahrenheit (14°C - 17°C) and lows generally in the low 40s (5°C - 7°C). The city receives an average of 14 to 15 inches of rainfall annually, almost entirely between November and April. Snowfall is exceptionally rare on the valley floor, though a light dusting is occasionally visible on the peaks of the eastern foothills during severe winter storms. Like much of the Bay Area, Milpitas sits near major fault lines, including the Hayward and Calaveras faults, making it susceptible to earthquakes.