Granite County Climate
Granite County, Montana
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
42.5°F
Annual Precip
14.3"
Annual Snowfall
30.5"
Extreme Heat Days
15
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
5b
Minimum winter temperature range for plant survival
1,324
Limited to cold-tolerant varieties
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Granite County
Climate Verdict
Granite County has a cool, averaging 42.5°F annually, arid conditions receiving just 14.3 inches of precipitation annually, rare extreme heat with only 15 days above 90°F annually, moderate snowfall of 30.5 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 24.2°F. summers are pleasantly cool with July averaging 63.7°F. The 39°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and July the warmest.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Granite County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Granite County closely matches the Montana statewide average temperature of 43.7°F.
Climate Profile
About Granite County Weather
A cool and dry mountain climate
Granite County records an annual average temperature of 42.5°F, staying well below the national average. The 14.3 inches of annual precipitation reflect a dry environment common to the western interior.
Just below the Montana state average
Granite County is slightly cooler than the state average of 43.7°F, coming in at 42.5°F. This reflects its position within the higher elevations of western Montana.
Comparable to Jefferson and Lake counties
The county's 42.5°F average is nearly identical to Jefferson County's 42.6°F. However, it is significantly cooler than Lake County, which enjoys a warmer 45.9°F average.
Balanced seasons with moderate snowfall
Winters are cold but manageable with a 24.2°F January average and 30.5 inches of snow. Summers are pleasant and mild, with only 15 days exceeding 90°F and a July average of 63.7°F.
Prioritize winter gear over summer cooling
With only 15 extreme heat days, high-end cooling is less critical than in other parts of the state. Residents should focus on winterizing homes for the 30 inches of snow and sub-freezing winter averages.
Frequently Asked Questions
What is the average temperature in Granite County?
How much rain does Granite County get?
Does it snow in Granite County?
How hot does Granite County get in summer?
How cold are winters in Granite County?
Track your own weather in Granite County
Ambient Weather personal weather stations give you hyperlocal climate data.
Sponsored
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.