California Weather In January 2025. Rainfall in san jose, in january, it is raining for 6.3 days, with typically 0.63 (16mm) of accumulated precipitation. Average monthly weather with temperature, pressure, humidity, precipitation, wind, daylight, sunshine, visibility, and uv index.
Insights into temperature, precipitation, and weather trends. Expect 20°c daytime maximum temperatures in the shade with on average 7 hours of sunshine per day in california in january.