About Sumter, SC's Climate & Weather History

With a population of around 40,800, Sumter sits in South Carolina, United States. The city operates in the Eastern Time Zone.

In 2025, Sumter recorded an average annual temperature of 65°F. The hottest temperatures reached 103°F in July; the coolest were 19°F in December. Total precipitation for the year was 40 inches, with the wettest month being May. Snowfall for the year totaled approximately 1 inches.