Union County Climate
Union County, South Carolina
Avg Annual Temp
61.0°F
Annual Precip
44.3"
Annual Snowfall
1.6"
Extreme Heat Days
59.55
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Seasonal Overview
National Comparison
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 source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.
Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.