Grayville, IL Climate

Climate Insight: Grayville, IL

Based on station USC00113612 feeding NOAA's 1991–2020 climate normals, Grayville, Illinois averages 56°F a year, ranging from a mean daily high of 67°F to a mean daily low of 46°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.

Grayville averages 50.0 inches of precipitation a year, with 11.8 inches typically falling as snow, and that matters as much to daily life here as temperature does. The frost-free season averages 201 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 7 and the first fall freeze near October 25. As for energy demand, 4,584 heating degree days and 1,424 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Grayville scores 78/100 (Good), 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.