World Resorts USA Rapid City Weather

Rapid City weather in September

Weather in Rapid City: September

Average day temperature: 76.9°F
Average night temperature: 57.9°F
Number of sunny days: 23 days
Day length: 11.8 - 13.2 hours
Number of rainy days: 1 day
Precipitation totals: 0.3 in.

Air temperature in September, °F

Show year:
2025
2024
2023

The highest day temperature during September of 2025 was 90°F. At the same time the lowest night temperature was 46°F. Daily and nightly averages during September were 76.4°F and 58.3°F.

Sunny, partly cloudy and cloudy days

Mostly all days in September are sunny but cloudy days are also possible.

Precipitation total in September, in.

Precipitation total value in Rapid City in September is 0.3 in. Other months of the year show relatively similar values.

Wind speed in September, mph

The average wind speed value in September is 8.2 mph It makes September one of the least windy months of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 10.2.

Best time for vacation in Rapid City

Sunniest months:
September 23 days
August 22 days
October 21 days
Warmest months:
July 84.4 °F
August 83.4 °F
September 76.9 °F
Coldest months:
February 31.7 °F
January 32.3 °F
December 36.1 °F
Rainiest months:
May 2 days
April 1 day
June 1 day
Windiest months:
April 10.1 mph
December 9.2 mph
November 9.0 mph

Rapid City on a weather map

Rapid City
+34°F
E 7 mph
Feels like: +28°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+77°F
+77°F
+45°F
+55°F
+70°F
+77°F
+70°F
+25°F
+57°F
+48°F
+63°F
+63°F
+46°F
+9°F
24 Hours Forecast
Rapid City
Local time: 21:12
December 05, friday
0000
34°F
E
6 mph
0300
28°F
E
6 mph
0600
30°F
SE
9 mph
0900
30°F
SE
13 mph
1200
39°F
SE
19 mph
1500
41°F
SE
19 mph
1800
36°F
S
6 mph
2100
28°F
N
6 mph
Units of measurement: °C / °F