Onarga, in Illinois, United States, is home to roughly 1,300 people in the Central Time Zone at 40.7°N latitude.
In 2025, Onarga recorded an average annual temperature of 53°F — right at the 30-year normal of 52°F. The hottest day reached 92°F in July; the coldest was -6°F in January. Total precipitation was 31 inches (drier than usual). The wettest month was July.
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