With a population of around 13,500, Riverdale sits in Illinois, United States. The city operates in the Central Time Zone.
In 2025, Riverdale recorded an average annual temperature of 51°F — about 0.9°F below the 30-year normal of 52°F. The hottest day reached 96°F in July; the coldest was -8°F in February. Total precipitation was 36 inches (near normal). The wettest month was July.
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