Rapid City (zip 57702), South Dakota, gets 21 inches of rain per year. The US average is 37. Snowfall is 53 inches. The average US city gets 25 inches of snow per year. The number of days with any measurable precipitation is 76.
On average, there are 226 sunny days per year in Rapid City (zip 57702), South Dakota. The July high is around 83 degrees. The January low is 12. Our comfort index, which is based on humidity during the hot months, is a 60 out of 100, where higher is more comfortable. The US average on the comfort index is 44.