Annual mean 8°C · wettest around May · prevailing wind N
Warmest
28.5 °C
Coldest
-2.0 °C
Wettest
24%
Windiest
7.0 m/s
Prevailing
N
5.5 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in Rapid City over the whole year is 8°C. July is the hottest month, with highs of about 28°C; February is the coldest, with lows of about -7°C. The rainy (wet) season in Rapid City runs from February to September, peaking in May with a 22% chance of rain on a given day. The dry season is October to January; December is the driest month, at 7%. Winds in Rapid City are highest in April, averaging 5.2 m/s (19 km/h), and lightest in July, at 3.7 m/s (13 km/h). The prevailing wind is from the N. The clearest skies in Rapid City come in July, when the sky is typically 19% covered; May is the cloudiest month, at 42%.
Month by month Rapid City climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
-0°C
-6°C
-7°C
14%
38%
4.1 m/s
0
0
5
February
-1°C
-7°C
-7°C
16%
41%
4.2 m/s
1
0
10
March
6°C
-2°C
-1°C
15%
41%
4.6 m/s
3
0
22
April
10°C
2°C
4°C
22%
40%
5.2 m/s
12
0
38
May
17°C
9°C
12°C
22%
42%
4.4 m/s
37
4
65
June
24°C
15°C
21°C
20%
25%
4.1 m/s
70
29
57
July
28°C
18°C
26°C
21%
19%
3.7 m/s
61
57
29
August
27°C
16°C
24°C
20%
19%
3.7 m/s
65
46
40
September
23°C
11°C
18°C
18%
24%
4.0 m/s
63
20
61
October
13°C
4°C
7°C
11%
29%
4.4 m/s
26
1
52
November
8°C
-1°C
1°C
7%
30%
4.2 m/s
6
0
29
December
1°C
-5°C
-5°C
7%
32%
4.4 m/s
1
0
10
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short Rapid City weather by season
Year round, Rapid City has days of about -1°C at their warmest in February, its coolest month, and 28°C in July, its warmest; the coolest hours of the day run from -7°C to 18°C through the year, and the average temperature over the year is 8°C around the clock. Rain is most likely around May and least likely around December. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
Rapid City weather in winterDecember to February
High 0°CLow -6°CRain 12%
Winter in Rapid City has typical daily highs of about 0°C and lows of about -6°C, with a 12% chance of rain on a given day.
Rapid City weather in springMarch to May
High 11°CLow 3°CRain 20%
Spring in Rapid City has typical daily highs of about 11°C and lows of about 3°C, with a 20% chance of rain on a given day.
Rapid City weather in summerJune to August
High 26°CLow 16°CRain 20%
Summer in Rapid City has typical daily highs of about 26°C and lows of about 16°C, with a 20% chance of rain on a given day.
Rapid City weather in autumnSeptember to November
High 14°CLow 5°CRain 12%
Autumn in Rapid City has typical daily highs of about 14°C and lows of about 5°C, with a 12% chance of rain on a given day.
When is the rainy season in Rapid City?
The rainy (wet) season in Rapid City runs from February to September, peaking in May with a 22% chance of rain on a given day. The dry season is October to January; December is the driest month, at 7%.
What time of year is Rapid City windiest?
Winds in Rapid City are highest in April, averaging 5.2 m/s (19 km/h), and lightest in July, at 3.7 m/s (13 km/h). The prevailing wind is from the N.
What is the average temperature in Rapid City year round?
The average temperature in Rapid City over the whole year is 8°C. July is the hottest month, with highs of about 28°C; February is the coldest, with lows of about -7°C.