The summer of 2021 (months of June, July, and August) was one of the warmest on record in the Black Hills. The downtown Rapid City NWS office recorded an average temperature (averaging the high and low temperature for each day) of 75.2 degrees, which ranks second behind 1936 when the average temperature was 76.1 degrees. The average maximum temperature of 87.9 degrees is the third highest. The summer of 1936 again is the hottest with an average maximum temperature of 89.5 degrees.

Rapid City Regional Airport's average temperature for the summer was 72.5 degrees, which ranks as the seventh warmest summer, and the average maximum temperature of 88.4 degrees is the sixth warmest. The records for both were set in 1988 when the average temperature was 74.7 degrees and average maximum temperature was 90.6 degrees.

Rankings for additional stations in the Black Hills region will be added when their data is available.