With a population of around 6,300, South Williamsport sits in Pennsylvania, United States. The city operates in the Eastern Time Zone.
In 2025, South Williamsport recorded an average annual temperature of 51°F — about 0.8°F below the 30-year normal of 51°F. The hottest day reached 96°F in June; the coldest was -5°F in January. Total precipitation was 43 inches (near normal). Snowfall totaled 7 inches, below the 36-inch average. The wettest month was May.
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