Kaskaskia Rvr Navigation Lock, IL Climate

Climate Insight: Kaskaskia Rvr Navigation Lock, IL

An annual average temperature of 56°F, ranging from a mean daily high of 67°F to a mean daily low of 46°F is what the NOAA 1991–2020 climate normals report for Kaskaskia Rvr Navigation Lock, Illinois. July is typically the warmest month of the year, while January is the coldest. That baseline comes from station USC00114629 and thirty years of averaging, so it reflects a typical month rather than any one year's swings.

Kaskaskia Rvr Navigation Lock averages 42.8 inches of precipitation a year, with 4.3 inches typically falling as snow, and that matters as much to daily life here as temperature does. The frost-free season averages 205 days, which directly shapes the planting calendar and growing potential for the area, with the last spring freeze near April 8 and the first fall freeze near October 30. As for energy demand, 4,576 heating degree days and 1,461 cooling degree days tell the story of how often furnaces and air conditioners run during a normal year.

On PlainClimate's composite comfort index, Kaskaskia Rvr Navigation Lock scores 83/100 (Excellent), 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.