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.
The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1991 to 2020 weather.
| High °F | Low °F | High °C | Low °C | |
|---|---|---|---|---|
| 36 | 13 | January | 2 | -11 |
| 38 | 14 | February | 3 | -10 |
| 48 | 23 | March | 9 | -5 |
| 57 | 31 | April | 14 | 0 |
| 67 | 42 | May | 19 | 5 |
| 78 | 52 | June | 25 | 11 |
| 86 | 59 | July | 30 | 15 |
| 85 | 56 | August | 30 | 13 |
| 76 | 46 | September | 25 | 8 |
| 60 | 34 | October | 16 | 1 |
| 47 | 22 | November | 9 | -6 |
| 37 | 14 | December | 3 | -10 |
| 60 | 34 | Year | 15 | 1 |
| 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 at Rapid City have highs in the 80s Fahrenheit. Normally 32 days a year reach 90 degrees, and an average of five days annually spike to 100 °F (38 °C) or more.
| 70 °F 21 °C |
80 °F 27 °C |
90 °F 32 °C | |
|---|---|---|---|
| January | 0 | 0 | 0 |
| February | 1 | 0 | 0 |
| March | 3 | 0 | 0 |
| April | 6 | 2 | 0 |
| May | 13 | 4 | 1 |
| June | 25 | 14 | 4 |
| July | 30 | 25 | 12 |
| August | 30 | 25 | 11 |
| September | 22 | 13 | 4 |
| October | 9 | 3 | 0 |
| November | 2 | 0 | 0 |
| December | 0 | 0 | 0 |
| Year | 140 | 86 | 32 |
How Often Rapid City Has Cold Temperatures
Rapid City typically has 174 nights below freezing a year, that show up from September to May. Eighteen of the coldest winter nights drop down to 0 °F (-18 °C) or lower.
For an average of 43 days annually the thermometer never rises above freezing. Days that chilly can occur from October to April.
| 0 °F -18 °C |
10 °F -12 °C |
20 °F -8 °C |
|
|---|---|---|---|
| January | 6 | 12 | 21 |
| February | 5 | 10 | 18 |
| March | 2 | 4 | 10 |
| April | 0 | 1 | 3 |
| May | 0 | 0 | 0 |
| June | 0 | 0 | 0 |
| July | 0 | 0 | 0 |
| August | 0 | 0 | 0 |
| September | 0 | 0 | 0 |
| October | 0 | 1 | 2 |
| November | 1 | 4 | 12 |
| December | 4 | 10 | 21 |
| Year | 18 | 41 | 88 |
References
Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Month and Year, Version 1.0. NOAA National Centers for Environmental Information.
NOAA National Centers for Environmental Information (NCEI). Climate Normals.