With a population of around 7,500, Marengo sits in Illinois, United States. The city operates in the Central Time Zone.
In 2025, Marengo recorded an average annual temperature of 50°F — right at the 30-year normal of 49°F. The hottest day reached 94°F in June; the coldest was -12°F in February. Total precipitation was 33 inches (drier than usual). Snowfall totaled 10 inches, below the 37-inch average. The wettest month was July.
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