Black Hills Climate Overview

This article describes typical weather conditions in the Black Hills region based on long-term climatic records. It is not a forecast and actual conditions can vary considerably from these values. Averages for other cities in the region are included to provide a comparison to Rapid City.

For forecasts, check the front page of this web site or listen to one of the NOAA Weather Radio stations serving the Black Hills area.

January and February are the coldest months of winter. Daytime temperatures average in the 30s, but Chinook winds can warm temperatures into the 50s and 60s. Occasional intrusions of Arctic air are short-lived and temperature inversions sometimes produce warmer conditions in the Black Hills.

Low temperatures average from 10 to 20 degrees above zero. Below zero readings are not uncommon in the higher valleys of the Black Hills.

Average monthly snowfall ranges from five inches in Rapid City to 15 inches in the Black Hills. The snow on the plains usually melts within a few days, with deeper snow in the Black Hills providing good winter recreation conditions.

March and April is western South Dakota’s snow season and temperatures are still cool enough in the higher elevations to retain the snow cover. March is typically the snowiest month of the year, with average snowfall 15 to 25 inches in the northern Black Hills and eight to 12 inches over the southern Hills. Normal highs are in the 40s and lows are in the 20s.

Snow often occurs in April, although temperatures are warmer. Normal snowfall for the Black Hills is 10 to 20 inches in the north and five to 10 inches in the south. Average daytime temperatures are in the 50s with lows in the 20s and 30s.

May and June weather is mild and precipitation changes from rain showers to thunderstorms. Storms typically develop over the Black Hills during the afternoon and move onto the plains in the evening. However, Rapid City still sees an average of 20 clear to partly cloudy days and 65 percent of its possible sunshine in June.

Temperatures warm rapidly as summer approaches. Daytime highs average in the 60s during May and 70s during June. Overnight temperatures are still chilly, especially in Black Hills, where May minimums are in the 30s and 40s. Lows are typically in the 40s and 50s during June.

Summer is warm, dry, and sunny. July and August are the warmest months of the year, when daytime temperatures climb into the 70s and 80s--and sometimes 90s. Breezy winds and low humidity levels help make the hot days comfortable.

Early mornings are cool, so a jacket or sweater may be needed for outdoor activities. Low temperatures average in the 50s, although 40s--and even 30s--can occur at the higher elevations like Deerfield.

Thunderstorms produce less rainfall, and drier conditions increase the wildfire potential in the Black Hills. Rapid City records an average of 9 thunderstorms days in August, but only 1.67 inches of rain.

Rapid City receives 75 percent of its possible sunshine. Because the elevation of the Black Hills are between 4000 and 7000 feet, the sun is very intense.

Sunny, mild days and cool nights are characteristic of September and October weather. Temperatures begin to cool around Labor Day, with September highs averaging in the 60s and 70s, falling into the 50s and 60s in October. Lows drop from the 30s and 40s into the 20s and 30s. The average first freeze in Rapid City is October 4 and late August through September in the Black Hills.

The area’s first snowfall is usually in October, although higher elevations sometimes receive snow in September. Occasional cold fronts moving through the area bring blustery northwest winds.

November and December mark the beginning of winter in the Black Hills. Despite cooler temperatures and more snow; the area still has many mild, sunny days.

By December, daytime temperatures are in the 30s with nighttime readings in the teens and sometimes below zero in the Black Hills. Occasionally cold air from Canada will bring subzero temperatures to the entire area; however, warmer weather returns quickly.

Snowfall averages about five inches each month with only two days typically receiving more than one inch of snow. Storms early in the season produce heavy, wet snow. As the winter progresses, storm tracks from the northwest bring drier snow. Rapid City’s chances for a white Christmas (defined as having inch or more of snow on the ground) is about 50 percent.