Custer County Climate
Custer County, Montana
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
46.4°F
Annual Precip
14.1"
Annual Snowfall
29.9"
Extreme Heat Days
44
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
4b
Minimum winter temperature range for plant survival
2,633
Supports most vegetables & fruits
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Custer County
Climate Verdict
Custer County has a cool, averaging 46.4°F annually, arid conditions receiving just 14.1 inches of precipitation annually, occasional hot days — 44.06666666666666 per year above 90°F, moderate snowfall of 29.9 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 20.1°F. summers are warm — July averages 74.0°F. Residents experience a substantial 54°F difference between winter and summer.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Custer County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Custer County closely matches the Montana statewide average temperature of 43.7°F, the county experiences 22.40212159863945 more extreme heat days than the state average.
Climate Profile
About Custer County Weather
A warmer pocket in a cold state
Custer County maintains an annual average temperature of 46.4°F, which sits well below the national median but remains notably warm for the Northern Rockies. The region experiences a semi-arid climate characterized by low humidity and 14.1 inches of annual precipitation.
Leading the state in heat
With an average temperature 2.7°F higher than the Montana state average of 43.7°F, Custer ranks as one of the state's warmer jurisdictions. It receives slightly less moisture than the state average of 15.4 inches, defining it as a dry, temperate outlier.
Competing with eastern neighbors
Custer’s climate mirrors Dawson County to the northeast, which is slightly warmer at 46.6°F. However, it is significantly warmer than Fallon County, where the average temperature drops to 44.0°F.
Sweltering summers and moderate snow
Residents face 44 days of extreme heat above 90°F, a high frequency for Montana, while July averages reach 74.0°F. Winter brings a manageable 29.9 inches of snow, much lower than the heavy totals found in the western mountains.
Preparing for the heat
Because summer temperatures frequently spike, high-efficiency cooling systems are a priority for local homeowners. Gardeners should prioritize drought-resistant plants to accommodate the low 14.1-inch annual rainfall.
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.