Vermillion, SD Climate

Climate Insight: Vermillion, SD

Based on station USC00398622 feeding NOAA's 1991–2020 climate normals, Vermillion, South Dakota averages 49°F a year, ranging from a mean daily high of 61°F to a mean daily low of 37°F. July is typically the warmest month of the year, while January is the coldest. Because these figures are thirty-year averages rather than any single year's readings, they describe the typical month, not a forecast for it.

Rainfall (and snow, where it falls) shapes day-to-day life here as much as temperature does. Vermillion sees about 28.0 inches of precipitation a year, predominantly as rainfall. The frost-free season averages 153 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near May 3 and the first fall freeze near October 3. On the energy side, 6,758 heating degree days and 904 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Vermillion scores 64/100 (Good), a blended measure that weighs temperature mildness, precipitation moderation, and extreme-weather frequency against one another. For planning purposes, look to the monthly tables above: shoulder seasons bring the mildest highs and lows, summer brings July-driven heat, and deep winter brings January-driven cold. Treat every figure here as a thirty-year average rather than a forecast - individual years routinely run warmer, cooler, wetter, or drier than the normal.