Rapid City climate — normals and trends
Rapid City (United States) has a warm-summer humid continental climate (Dfb) under the Köppen-Geiger classification. Its mean annual temperature is 7.7 °C and it receives 631 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is July (21.3 °C on average) and the coldest is January (-4.3 °C). Rainfall peaks in May.
Rapid City averages 155 frost days, 26 hot days (≥ 30 °C) and 108 rainy days per year.
Rapid City has warmed by +1.2 °C between 1940 and 2025, or +0.14 °C per decade. This trend is statistically significant.
The number of frost days there went from about 160 to 150 per year over the period.
The hottest day of the period reached 40.5 °C (on 15 July 2006) and the coldest -36.2 °C (on 22 December 1989).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
Rapid CitySouth Dakota
- coords
- 44.08°, -103.23°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
7.7°C
Average daily high
13.9°C
Average daily low
1.9°C
Annual rainfall
631mm
Sunshine / day
10.1h
Mean relative humidity
60%
Average peak wind
19.6km/h
Seasonal range
25.6°C
Frost days (< 0 °C)
155 d/yr
Hot days (≥ 30 °C)
26 d/yr
Rainy days (≥ 1 mm)
108 d/yr
Annual snowfall
107.7 cm
Average feels-like high
10.8 °C
Average feels-like low
-1.9 °C
Average peak gust
40.4 km/h
Tropical nights (≥ 20 °C)
2 d/yr
Solar radiation
16.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.2 °C
since 1940
+0.1 °C per decade · r² = 0.18 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
40.5 °C
15 July 2006
Coldest day
-36.2 °C
22 December 1989
Wettest day
93 mm
4 July 1979
Windiest day
57.9 km/h
3 March 1966
Strongest gust
117.0 km/h
19 April 2006
Hottest feels-like
39.6 °C
15 July 2006
Coldest feels-like
-41.3 °C
22 December 1989
Snowiest day
48.4 cm
4 October 2013
Sunniest day
15.1 h
27 June 1980
Normals computed over complete calendar years 1940–2025.
A specific year
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Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | -0.3 °C | -1.8 °C | 10 mm | -5 mm |
| Feb | -0.9 °C | -3.6 °C | 13 mm | -8 mm |
| Mar | 11.2 °C | +4.5 °C | 29 mm | -11 mm |
| Apr | 14.0 °C | +1.7 °C | 61 mm | -18 mm |
| May | 18.4 °C | +0.7 °C | 100 mm | -8 mm |
| Jun | 25.2 °C | +1.8 °C | 88 mm | -13 mm |
| Jul | 28.0 °C | +0.2 °C | 82 mm | -1 mm |
| Aug | 27.3 °C | +0.1 °C | 64 mm | +3 mm |
| Sep | 24.8 °C | +2.7 °C | 25 mm | -19 mm |
| Oct | 16.8 °C | +1.7 °C | 43 mm | +2 mm |
| Nov | 10.7 °C | +3.5 °C | 12 mm | -10 mm |
| Dec | 7.3 °C | +4.8 °C | 17 mm | +0 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Rapid City?
Rapid City has a warm-summer humid continental climate (Köppen Dfb). Over 1940-2025, the average annual temperature is 7.7 °C and it receives 631 mm of precipitation per year.
What is the hottest day ever recorded in Rapid City?
The hottest day measured in Rapid City between 1940 and 2025 was 15 July 2006, reaching 40.5 °C.
What is the coldest day in Rapid City?
The coldest day measured in Rapid City between 1940 and 2025 was 22 December 1989, at -36.2 °C.
Does it snow in Rapid City?
Yes. Rapid City gets on average 107.7 cm of snow per year and has around 155 frost days.
Has the climate of Rapid City warmed?
Yes: Rapid City warmed by +1.2 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Rapid City?
The wettest day measured in Rapid City between 1940 and 2025 was 4 July 1979, with 93 mm of rain in 24 hours.
What was the windiest day in Rapid City?
The windiest day measured in Rapid City between 1940 and 2025 was 3 March 1966, with winds reaching 57.9 km/h.
What is the warmest month in Rapid City?
The warmest month in Rapid City is July (21.3 °C on average); the coldest is January (-4.3 °C).
How much does it rain in Rapid City?
Rapid City receives on average 631 mm of precipitation per year, spread over about 108 rainy days.
Is it sunny in Rapid City?
Rapid City gets on average 10.1 hours of sunshine per day, roughly 3,687 hours per year over 1940-2025.
What is the biggest single-day snowfall in Rapid City?
The heaviest 24-hour snowfall measured in Rapid City between 1940 and 2025 was 4 October 2013, with 48.4 cm.
Are there tropical nights in Rapid City?
Yes: Rapid City has on average 2 tropical nights per year (temperature staying above 20 °C), over 1940-2025.
What was the most extreme apparent temperature in Rapid City?
In Rapid City, between 1940 and 2025, the highest apparent temperature reached 39.6 °C on 15 July 2006, and the lowest was -41.3 °C on 22 December 1989.
Compare Rapid City with another city
Pick a second city: its normals will be set against these, indicator by indicator.