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Custer County Climate

Custer County, South Dakota

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec45.2°AVG °F

Avg Annual Temp

45.2°F

Annual Precip

19.5"

Annual Snowfall

43.0"

Extreme Heat Days

14

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.4"
0.6"
0.9"
2.1"
3.4"
3.2"
2.9"
2.2"
1.4"
1.3"
0.6"
0.4"
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

2,041

Favors cool-season crops

Last spring frost (32°F): 05/18
First fall frost (32°F): 09/28

Seasonal Overview

Comfort ZoneSpring35°51°6.4"Summer62°69°8.3"Fall34°59°3.3"Winter26°26°1.4"20°40°60°80°100°

National Comparison

Warmer than 13% of US counties
Wetter than 14% of US counties
More seasonal variation than 53% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Custer County

Climate Verdict

Custer County has a cool, averaging 45.2°F annually, semi-arid conditions with only 19.5 inches of annual precipitation, rare extreme heat with only 13.549999999999999 days above 90°F annually, moderate snowfall of 43.0 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 25.5°F. summers are pleasantly cool with July averaging 69.2°F. The 44°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Custer County closely matches the South Dakota statewide average temperature of 45.6°F, it is somewhat drier than average for South Dakota.

Climate Profile

About Custer County Weather

Temperate Mountain and Plains Blend

Custer County maintains an average temperature of 45.2°F, which is cool by national standards. The area is relatively dry, receiving 19.5 inches of annual precipitation.

Typical South Dakota Average Temperature

Custer's 45.2°F annual average is almost identical to the South Dakota state average of 45.6°F. However, its 19.5 inches of precipitation is lower than the state's 22.7-inch average.

Milder Winters Than Northern Neighbors

Custer shares a similar annual temperature with Butte County, but enjoys much warmer Januarys at 25.5°F. It is also significantly snowier, receiving 43 inches compared to Butte's 41.7 inches.

Heavy Snow and Mild Summers

Summer in Custer is pleasant with only 14 days of extreme heat and a July average of 69.2°F. Winter is the dominant season, bringing the highest snowfall on this list at 43 inches.

Equip for Serious Snow Management

The 43 inches of annual snow requires high-quality winter gear and reliable four-wheel drive. Because summer temperatures are mild, residents can often rely on natural ventilation instead of heavy air conditioning.

Frequently Asked Questions

What is the average temperature in Custer County?
The average annual temperature in Custer County, SD is 45.2°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Custer County get?
Custer County receives an average of 19.5 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 Custer County?
Yes, Custer County receives an average of 43.0 inches of snowfall per year according to NOAA climate normals.
How hot does Custer County get in summer?
The average summer temperature (June-August) in Custer County is 66.2°F. The county experiences an average of 14 days per year above 90°F.
How cold are winters in Custer County?
The average winter temperature (December-February) in Custer County is 25.9°F. January, typically the coldest month, averages 25.5°F.

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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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