Sparta, WI Climate

Climate Insight: Sparta, WI

In Sparta, Wisconsin, the NOAA 1991–2020 climate normals put the annual average temperature at 45°F, ranging from a mean daily high of 55°F to a mean daily low of 34°F. July is typically the warmest month of the year, while January is the coldest. As thirty-year averages computed from station USC00477997, these numbers smooth out year-to-year noise into a working baseline for a typical month.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Sparta sees about 35.6 inches of precipitation a year, predominantly as rainfall. The frost-free season averages 145 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near May 9 and the first fall freeze near October 1. On the energy side, 7,935 heating degree days and 536 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Sparta scores 54/100 (Moderate), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. The monthly tables above turn that into a planning tool: expect the mildest highs and lows in the shoulder seasons, July-driven heat at the peak of summer, and January-driven cold at the depth of winter. Every number here is a thirty-year average, not a forecast, so any given year can and does run warmer, cooler, wetter, or drier than the normal.