Rapid City Temperatures: Averages by Month





The numbers here tell you how hot and cold the weather usually is in Rapid City, South Dakota during each month of the year.

The average high and low temperatures are listed below monthly and annually for the city, in both degrees Fahrenheit and Celsius.

Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.

To find out how often it rises over 70, 80 or 90 °F each month in Rapid City, scroll down farther. There are also monthly and yearly counts of days with cold weather.

All the numbers are long-term historical averages based on climate data gathered from 1981 to 2010.

Average Rapid City temperatures
High °F Low °F   High °C Low °C
37 16 January 3 -9
39 18 February 4 -8
47 25 March 8 -4
56 34 April 13 1
66 45 May 19 7
76 54 June 24 12
84 62 July 29 17
84 60 August 29 15
73 50 September 23 10
59 38 October 15 3
46 28 November 8 -3
37 18 December 3 -8
59 37 Year 15 3

Days of Hot Weather in Rapid City

Most summer days stay quite comfortable at Rapid City with highs in the 70s or 80s Fahrenheit. Normally 18 days a year reach 90 degrees and one day spikes to 100 or more.

Number of days in Rapid City of at least 70, 80 or 90 °F
  70 °F
21 °C
80 °F
27 °C
90 °F
32 °C
January 0 0 0
February 0 0 0
March 0 0 0
April 4 1 0
May 12 3 0
June 23 10 2
July 29 22 8
August 30 21 6
September 17 9 2
October 7 1 0
November 2 0 0
December 0 0 0
Year 126 68 18

How Often Rapid City Has Cold Temperatures

Rapid City typically has 141 frosty nights a year that show up from October to May. A dozen of the coldest winter nights drop down to 0 °F (-18 °C) or lower.

For an average of 42 days annually the thermometer never rises above freezing. Days that chilly can occur from October to April.

Days per month on average in Rapid City when the minimum temperature drops to 20, 10 or 0 °F or below
  0 °F
-18 °C
10 °F
-12 °C
20 °F
-8 °C
January 5 10 17
February 3 7 14
March 1 3 9
April 0 0 2
May 0 0 0
June 0 0 0
July 0 0 0
August 0 0 0
September 0 0 0
October 0 0 1
November 1 2 7
December 3 8 16
Year 12 31 66
Reference

National Climatic Data Center. NOAA's 1981-2010 Climate Normals.

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