The summer of 2011 was near average, with both temperatures and precipitation slightly above normal. For the purpose of climate statistics, the summer season is June 1 through August 31.
Rapid City Regional Airport’s average temperature was 70.3 degrees, which is 0.7 degrees above normal. Temperatures ranged from 103 degrees on July 31 to 39 degrees on June 1. The airport had 31 days with a high temperature of 90 degrees or warmer compared to the average of 25 days.
The precipitation total was 6.25 inches, which is 0.31 inches above normal. While the total rainfall for the summer was near normal, over half the amount fell in June: 3.84 inches, which was 1.01 inches above normal while July had only 0.66 inches, a deficit of 1.37 inches. Of the 46 days with measurable precipitation, only five had 0.50 inches or more and one day received more than an inch of rain. The greatest 24 hour total was 1.14 inches on June 25-26.
The average temperature at the downtown Rapid City National Weather Service office was 70.9 degrees, which is 0.9 degrees above normal. The warmest temperature was 101 degrees on June 29 while the coldest temperature was 42 degrees on June 1 and 11. Twenty-three days reached a maximum temperature of 90 degrees.
A total of 8.25 inches of precipitation was recorded, which was 0.62 inches above normal. Precipitation was measured on 58 days; eight days received 0.50 inch or more and three days had 1.00 inches or more. The greatest 24 hour total was 1.64 inches on June 25.
More statistics on the summer season are available at Rapid City Regional Airport Seasonal Climate Summary and Rapid City NWS Seasonal Climate Summary.