Douglas is a city of approximately 20,300 people in Illinois, United States. Located in the Central Time Zone at 41.8°N latitude.
In 2025, Douglas recorded an average annual temperature of 51°F — about 1.1°F below the 30-year normal of 52°F. The hottest day reached 96°F in June; the coldest was -7°F in February. Total precipitation was 33 inches (near normal). The wettest month was June.
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