Galena, IL Climate

Climate Insight: Galena, IL

An annual average temperature of 47°F, ranging from a mean daily high of 57°F to a mean daily low of 37°F is what the NOAA 1991–2020 climate normals report for Galena, Illinois. July is typically the warmest month of the year, while January is the coldest. That baseline comes from station USC00113312 and thirty years of averaging, so it reflects a typical month rather than any one year's swings.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Galena sees about 39.6 inches of precipitation a year, with 37.9 inches typically falling as snow. The frost-free season averages 172 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 26 and the first fall freeze near October 15. On the energy side, 7,134 heating degree days and 615 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Galena scores 59/100 (Moderate), 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 July-driven heat, or deep winter for January-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.