The temperatures in Rapid City in August are comfortable with low of 17°C and and high up to 29°C.
You can expect about 3 to 8 days of rain in Rapid City during the month of August. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Rapid City in August 2025.
If you’re planning to visit Rapid City in the near future, we highly recommend that you review the 14 day weather forecast for Rapid City before you arrive.
Temperatures
29° / 17°
Rainy Days
6
Snowy Days
0
Dry Days
25
Rainfall
96
mm
Sun Hours
11.9
Hrs
