Sumter County Climate
Sumter County, South Carolina
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
63.2°F
Annual Precip
47.5"
Annual Snowfall
0.6"
Extreme Heat Days
56
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
8b
Minimum winter temperature range for plant survival
5,451
Excellent for heat-loving crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Sumter County
Climate Verdict
Sumter County has a warm, averaging 63.2°F year-round, moderately wet with 47.5 inches of annual precipitation, occasional hot days — 55.55 per year above 90°F, light snow averaging 0.6 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are mild, with January temperatures averaging 45.2°F. summers are hot, with July averaging 80.3°F. The 35°F seasonal variation provides noticeable but manageable change.
Outdoor & Gardening Guidance
The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.
Regional Context
Sumter County closely matches the South Carolina statewide average temperature of 62.8°F.
Climate Profile
About Sumter County Weather
Warm and Sunny Midlands Climate
Sumter County averages 63.2°F annually, which is roughly 9 degrees higher than the U.S. median. Precipitation is consistent with the region at 47.5 inches per year. The humid subtropical climate ensures a long outdoor season and very mild winters.
Right in Line With State Averages
Sumter's annual average of 63.2°F is nearly identical to the South Carolina average of 62.8°F. Its rainfall of 47.5 inches is also very close to the state's 48.9-inch average. Sumter represents the quintessential climate of the South Carolina inner coastal plain.
Slightly Cooler Than its Neighbors
Sumter is slightly cooler than Richland (63.9°F) and Orangeburg (65.3°F) to the west and south. Interestingly, it has fewer extreme heat days (56) than both Richland (84) and Orangeburg (80). This provides a marginally more tempered summer experience than neighboring counties.
Hot Summers and Very Rare Snow
Summers are hot with 56 days reaching 90°F or more and a July average of 80.3°F. Snow is almost a non-factor, averaging only 0.6 inches per year. Winters are pleasant and mild, with temperatures averaging 47.0°F during the winter months.
Prioritize Sun Protection and AC
With 56 days of high heat, maintaining a reliable cooling system and using sun protection is vital. Residents only need light winter gear for the 45.2°F January average, as 0.6 inches of snow rarely impacts travel. The 47.5 inches of rain is well-distributed, but gardeners should plan for summer dry spells.
Frequently Asked Questions
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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.
Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.