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Stillwater County Climate

Stillwater County, Montana

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec44.0°AVG °F

Avg Annual Temp

44.0°F

Annual Precip

18.7"

Annual Snowfall

87.3"

Extreme Heat Days

19

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.6"
0.9"
1.2"
2.0"
3.3"
2.7"
1.6"
1.2"
1.5"
1.8"
1.0"
0.8"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5a

Minimum winter temperature range for plant survival

Growing Degree Days

1,635

Favors cool-season crops

Last spring frost (32°F): 06/01
First fall frost (32°F): 09/14

Seasonal Overview

Comfort ZoneSpring35°50°6.5"Summer58°66°5.6"Fall33°56°4.3"Winter26°27°2.3"20°40°60°80°100°

National Comparison

Warmer than 10% of US counties
Wetter than 12% of US counties
More seasonal variation than 35% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Stillwater County

Climate Verdict

Stillwater County has a cool, averaging 44.0°F annually, semi-arid conditions with only 18.7 inches of annual precipitation, rare extreme heat with only 19.45 days above 90°F annually, heavy winter snowfall averaging 87.3 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 26.1°F. summers are pleasantly cool with July averaging 65.9°F. The 40°F seasonal variation provides noticeable but manageable change. December is typically the coldest month and July the warmest.

Outdoor & Gardening Guidance

Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.

Regional Context

Stillwater County closely matches the Montana statewide average temperature of 43.7°F, it is somewhat wetter than average for Montana.

Climate Profile

About Stillwater County Weather

Average Temperatures, Extraordinary Snowfall

Stillwater County’s 44.0°F annual average is typical for the region, but its moisture patterns are unique. The county faces a heavy seasonal snow load compared to much of the United States.

Matching the Montana Temperature Baseline

Stillwater’s 44.0°F annual average is nearly identical to the Montana state average of 43.7°F. However, its 18.7 inches of precipitation makes it wetter than many other parts of the state.

A Regional Leader in Heavy Snow

While neighboring counties might see moderate totals, Stillwater gets buried under 87.3 inches of annual snowfall. This is nearly triple the snowfall seen in eastern Montana counties like Richland.

Mountain Winters and Gentle Summers

July averages a pleasant 65.9°F, while winter is defined by the massive 87.3-inch snow total. January temperatures stay relatively mild for the state at 26.1°F, despite the heavy precipitation.

Serious Snow Prep is Mandatory

With over 87 inches of snow per year, residents need professional-grade snow blowers and structural roof considerations. While 19 days of extreme heat occur, the primary planning focus should remain on winter moisture management.

Frequently Asked Questions

What is the average temperature in Stillwater County?
The average annual temperature in Stillwater County, MT is 44.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Stillwater County get?
Stillwater County receives an average of 18.7 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Stillwater County?
Yes, Stillwater County receives an average of 87.3 inches of snowfall per year according to NOAA climate normals.
How hot does Stillwater County get in summer?
The average summer temperature (June-August) in Stillwater County is 63.0°F. The county experiences an average of 19 days per year above 90°F.
How cold are winters in Stillwater County?
The average winter temperature (December-February) in Stillwater County is 26.3°F. January, typically the coldest month, averages 26.1°F.

Track your own weather in Stillwater County

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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.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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