Day County Climate
Day County, South Dakota
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
43.7°F
Annual Precip
24.1"
Annual Snowfall
40.1"
Extreme Heat Days
8
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
4b
Minimum winter temperature range for plant survival
2,522
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Day County
Climate Verdict
Day County has a cool, averaging 43.7°F annually, semi-arid conditions with only 24.1 inches of annual precipitation, rare extreme heat with only 7.933333333333334 days above 90°F annually, moderate snowfall of 40.1 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 12.3°F. summers are warm — July averages 71.5°F. Residents experience a substantial 59°F difference between winter and summer.
Outdoor & Gardening Guidance
Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.
Regional Context
Day County closely matches the South Dakota statewide average temperature of 45.6°F, the county experiences 15.596363247863245 fewer extreme heat days than the state average.
Climate Profile
About Day County Weather
A Cool Northern Continental Climate
Day County's 43.7°F average temperature is significantly cooler than the national median. This northern location brings sharp seasonal transitions and long, cold winters.
Chillier than the State Average
The county stays nearly 2 degrees cooler than the South Dakota average of 45.6°F. This makes it one of the state's chillier jurisdictions, particularly during the deep winter months.
Higher Precipitation than Western Peers
At 24.1 inches of annual precipitation, Day County is wetter than the state average of 22.7 inches. This extra moisture often translates to 40.1 inches of snow during the long winter season.
Mild Summers and Frigid Winters
January averages a frigid 12.3°F while July reaches a comfortable 71.5°F. The area only sees 8 days of 90-degree heat, offering a significant reprieve from the summer intensity felt elsewhere in the state.
Focus on Winter Readiness
High-quality winter gear is a priority here given the 15.8°F winter average and consistent snow accumulation. Residents enjoy lower summer cooling costs but must invest heavily in home insulation and heating reliability.
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.