Climate Insights for Rapid City

The climate in Rapid City is cool. The average annual temperature is 8°C and approximately 578mm of precipitation falls per year. May is the wettest month, receiving around 102mm of rainfall. Rapid City is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, August, June. The coldest months are February, January, December, when temperatures can drop to -9°C. Snowfall occurs from January to December, with around 141cm accumulating over the season.

Rapid City has a wide annual temperature range, spanning 38°C from the coldest to warmest months. The warmest month is July, when average highs reach 29°C and the mean temperature sits around 22°C. The coldest month is February, when overnight lows fall to -9°C and the daily average is -4°C. On average, daily temperatures fluctuate by about 12°C between overnight lows and afternoon highs. The sharpest temperature change occurs between September and October, with a 9°C shift in average temperatures.

Rapid City is a relatively dry area, receiving approximately 578mm of precipitation annually, which averages out to around 48mm per month. The wettest month is May, averaging 102mm of rainfall. July and June also tend to see above-average precipitation. The driest month is January, with just 14mm. That's 88mm less than May, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Snowfall is a regular feature from January to December, with around 141cm accumulating over the season. April typically sees the most snow at around 32cm.

Rapid City is mildly breezy, with an average annual wind speed of 12km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 14km/h, though still comfortable for most outdoor activities. The calmest conditions occur in July, with average winds dropping to 11km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h between the calmest and windiest months.

It is currently summer in Rapid City, which began on June 21, 2026. Rapid City is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 29°C, while the coldest stretch bottoms out in February near -9°C. Autumn is next, beginning on September 23, 2026 (7 days from now).

The best time to visit Rapid City is during June, July, August and September, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 63mm per month. By contrast, February can be quite cold with temperatures dropping to -9°C. A light rain jacket is recommended, though showers are generally brief and shouldn't disrupt your plans.

The table below shows monthly climate averages for Rapid City based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.