San Jose, CA Climate

Climate Insight: San Jose, CA

The NOAA 1991–2020 climate normals describe San Jose, California as a location with an annual average temperature of 61°F, ranging from a mean daily high of 71°F to a mean daily low of 50°F. August is typically the warmest month of the year, while December is the coldest. These thirty-year averages, computed from 2 weather stations, smooth out year-to-year variability and give a baseline expectation for typical conditions in any given month.

Precipitation patterns matter as much as temperature for anyone planning to live, garden, or travel here. San Jose receives roughly 13.5 inches of precipitation each year, with seasonal snowfall possible. Growing-season length varies with elevation and microclimate, with the last spring freeze near January 12 and the first fall freeze near December 22. For energy use, 2,184 heating degree days and 624 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, San Jose scores 77/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. Use the monthly tables above to plan around specific windows — shoulder seasons for mild highs and lows, peak summer for August-driven heat, or deep winter for December-driven cold. All figures here are thirty-year averages: any single year may run warmer, wetter, drier, or cooler than the normal, so treat them as planning guidance rather than forecasts.