With a population of around 13,500, Swansea sits in Illinois, United States. The city operates in the Central Time Zone.
In 2025, Swansea recorded an average annual temperature of 57°F — about 0.9°F below the 30-year normal of 58°F. The hottest day reached 97°F in July; the coldest was -0°F in February. Total precipitation was 43 inches (near normal). Snowfall totaled 6 inches, below the 11-inch average. The wettest month was April.
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