Union County Climate
Union County, South Carolina
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
61.0°F
Annual Precip
44.3"
Annual Snowfall
1.6"
Extreme Heat Days
60
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
8a
Minimum winter temperature range for plant survival
4,936
Excellent for heat-loving crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Union County
Climate Verdict
Union County has a warm, averaging 61.0°F year-round, moderately wet with 44.3 inches of annual precipitation, occasional hot days — 59.55 per year above 90°F, light snow averaging 1.6 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are mild, with January temperatures averaging 42.0°F. summers are warm — July averages 79.7°F. The 38°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
Union County closely matches the South Carolina statewide average temperature of 62.8°F, it is somewhat drier than average for South Carolina.
Climate Profile
About Union County Weather
Warmer than the national median
Union County’s 61.0°F average temperature sits well above the national median, placing it in a classic humid subtropical climate. Residents experience a significantly warmer profile than much of the continental U.S.
A cooler pocket of the Palmetto State
Compared to the South Carolina average of 62.8°F, Union is slightly cooler than many of its state peers. It ranks toward the cooler end of the state spectrum, reflecting its position in the Upstate region.
Drier than the coastal plains
Union shares a similar climate with York to the northeast but stays drier with 44.3 inches of annual rainfall. This is notably lower than the 48.9 inches averaged statewide, marking a more temperate interior environment.
Sixty days of intense summer heat
Summers are demanding with 60 days topping 90°F and a July average of 79.7°F. Winters provide a sharp contrast at a 44.0°F average, though the county only sees a light 1.6 inches of annual snow.
Prepare for a long cooling season
HVAC systems must be ready for two solid months of extreme heat days every year. While winter averages 42.0°F in January, residents can skip the heavy snow gear and focus on insulation for damp, chilly nights.
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.