San Jose, California weather in January

Averages from 2021–2025 (155 days of record).

Average high

59°F

Average low

43°F

Rainy days

~8 per month

Total precipitation

3.7 in

Warmest recorded

73°F

Coldest recorded

33°F

Expect January days in San Jose, California to top out around 59°F and cool to about 43°F overnight, with roughly 8 days of measurable rain across the month. In recent years January has ranged from 33°F to 73°F.