Island Lake is a city of approximately 8,100 people in Illinois, United States. Located in the Central Time Zone at 42.3°N latitude.
In 2025, Island Lake recorded an average annual temperature of 50°F — about 1.2°F below the 30-year normal of 51°F. The hottest day reached 94°F in June; the coldest was -10°F in February. Total precipitation was 32 inches (near normal). The wettest month was July.
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