Rapid City, SD Climate & Monthly Averages
The climate of Rapid City
Rapid City has a semi-arid climate, marked by big day-to-night temperature swings and modest rainfall. Average daytime highs range from about 37°F (3°C) in February to around 86°F (30°C) in July, and the city records roughly 81 days of measurable precipitation a year.
Climate quick facts
- Hottest month: July - highs near 86°F (30°C)
- Coldest month: February - highs near 37°F (3°C)
- Record high: 105°F (41°C) · Record low: -21°F (-30°C) (2015–2024)
- Wettest month: May (12 rainy days) · Sunniest: July (13.5 h sun/day)
- Climate type: semi-arid - big day-to-night temperature swings and modest rainfall
- Snow: about 22 days a year
Temperatures through the year
The warmest stretch of the year centers on July. Highs average 86°F (30°C) and overnight lows stay near 63°F (17°C). The coolest month is February, with typical highs of 37°F (3°C) and lows around 17°F (-8°C). Based on 2015–2024 weather data, temperatures have reached as high as 105°F (41°C) and dropped as low as -21°F (-30°C).
Rain, sun and snow
May is usually the wettest month. It brings about 3.4 inches (87 mm) of rain over 12 days, while January is the driest. July brings the most sunshine, averaging 13.5 hours of sun a day. Snow falls on about 22 days in a typical year, mostly from October through May.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 37° | 18° | 4 | 0.5 in | 7.2 h/day | 62% |
| February | 37° | 17° | 6 | 0.9 in | 8.2 h/day | 58% |
| March | 47° | 26° | 6 | 1.1 in | 9.3 h/day | 58% |
| April | 55° | 33° | 9 | 2.4 in | 10.2 h/day | 58% |
| May | 65° | 45° | 12 | 3.4 in | 10.9 h/day | 61% |
| June | 80° | 58° | 9 | 2.6 in | 13.1 h/day | 55% |
| July | 86° | 63° | 8 | 1.6 in | 13.5 h/day | 52% |
| August | 83° | 61° | 6 | 1.6 in | 12.6 h/day | 52% |
| September | 76° | 54° | 5 | 1.1 in | 10.6 h/day | 52% |
| October | 60° | 40° | 6 | 1.5 in | 8.9 h/day | 55% |
| November | 48° | 29° | 4 | 0.6 in | 7.7 h/day | 55% |
| December | 37° | 20° | 5 | 0.9 in | 6.8 h/day | 61% |
Rapid City month by month
Rapid City weather in January
January brings highs around 37°F (3°C), lows near 18°F (-8°C), about 4 wet days and roughly 2 snowy days - typically the driest month of the year in Rapid City.
Rapid City weather in February
February brings highs around 37°F (3°C), lows near 17°F (-8°C), about 6 wet days and roughly 4 snowy days - typically the coldest month of the year in Rapid City.
Rapid City weather in March
March brings highs around 47°F (9°C), lows near 26°F (-3°C), about 6 wet days and roughly 4 snowy days.
Rapid City weather in April
April brings highs around 55°F (13°C), lows near 33°F (1°C), about 9 wet days and roughly 4 snowy days.
Rapid City weather in May
May brings highs around 65°F (19°C), lows near 45°F (7°C), about 12 wet days - typically the wettest month of the year in Rapid City.
Rapid City weather in June
June brings highs around 80°F (26°C), lows near 58°F (14°C), about 9 wet days.
Rapid City weather in July
July brings highs around 86°F (30°C), lows near 63°F (17°C), about 8 wet days - typically the hottest month and the sunniest month of the year in Rapid City.
Rapid City weather in August
August brings highs around 83°F (28°C), lows near 61°F (16°C), about 6 wet days.
Rapid City weather in September
September brings highs around 76°F (25°C), lows near 54°F (12°C), about 5 wet days.
Rapid City weather in October
October brings highs around 60°F (16°C), lows near 40°F (4°C), about 6 wet days and roughly 2 snowy days.
Rapid City weather in November
November brings highs around 48°F (9°C), lows near 29°F (-2°C), about 4 wet days and roughly 2 snowy days.
Rapid City weather in December
December brings highs around 37°F (3°C), lows near 20°F (-7°C), about 5 wet days and roughly 4 snowy days.
Seasons in Rapid City
Spring (March through May)
Spring in Rapid City is mild, with daytime highs averaging 56°F (13°C) and nights around 35°F (2°C); expect showers on roughly 27 days across the season, plus around 8 snowy days.
Summer (June through August)
Summer in Rapid City runs hot, with daytime highs averaging 83°F (28°C) and nights around 61°F (16°C); expect showers on roughly 24 days across the season.
Fall (September through November)
Fall in Rapid City is mild, with daytime highs averaging 61°F (16°C) and nights around 41°F (5°C); rain falls on about 15 days over the three months, plus around 4 snowy days.
Winter (December through February)
Winter in Rapid City is frigid, with daytime highs averaging 37°F (3°C) and nights around 18°F (-8°C); rain falls on about 15 days over the three months, plus around 10 snowy days. Wind makes those temperatures feel harsher than they sound - pair the forecast winds with the wind speed converter to judge conditions on exposed skin.
Climate questions, answered
What is the average temperature in Rapid City?
Is Rapid City hot in summer?
Is Rapid City cold in winter?
How many rainy days does Rapid City get in a year?
Best time to visit Rapid City
The best time to visit Rapid City is generally August to October and May to June, when temperatures are at their most comfortable before or after the peak heat. Daytime temperatures in that window typically sit near 73°F (23°C).
Pack for Rapid City with lightweight, breathable clothing and strong sun protection for the hot months; a heavy insulated coat, hat and gloves for winter; rain gear if you travel around May. Evenings can feel noticeably cooler than afternoons - July nights average 63°F (17°C).
Rapid City temperature records (2015-2024)
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.