Collinsville, in Illinois, United States, is home to roughly 24,800 people in the Central Time Zone at 38.7°N latitude.
In 2025, Collinsville recorded an average annual temperature of 57°F — right at the 30-year normal of 57°F. The hottest day reached 96°F in July; the coldest was 0°F in January. Total precipitation was 43 inches (wetter than usual). The wettest month was April.
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