Climateby Month

Rapid City, SD climate by month

NOAA 1991-2020 normals · 3,243 ft elevation

Rapid City has warm summers and cold and snowy winters. Highs peak at 86°F in July and fall to 36°F in January. The wettest month is May (about 13 wet days) and the driest is December (about 5). Normal snowfall is about 54 in a year. By our comfort score the best months are May and June.

Warmest month
86°F
July normal high
Coldest month
13°F
January normal low
Wet days a year
96
17.4 in of precipitation
Snow a year
53.7 in
normal snowfall

How warm is Rapid City?

Normal highs range from 36°F in January to 86°F in July.

0°20°40°60°80°100° January: normal high 36°F (2°C), low 13°F (-11°C) 36° 13° February: normal high 38°F (3°C), low 14°F (-10°C) March: normal high 48°F (9°C), low 23°F (-5°C) April: normal high 57°F (14°C), low 31°F (-1°C) May: normal high 67°F (19°C), low 42°F (6°C) June: normal high 78°F (26°C), low 52°F (11°C) July: normal high 86°F (30°C), low 59°F (15°C) 86° 59° August: normal high 85°F (29°C), low 56°F (13°C) September: normal high 76°F (24°C), low 46°F (8°C) October: normal high 60°F (16°C), low 34°F (1°C) November: normal high 47°F (8°C), low 22°F (-6°C) December: normal high 37°F (3°C), low 14°F (-10°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Rapid City?

May has the most wet days (about 13); the year brings about 17 in of precipitation.

January: 6 wet days February: 7 wet days March: 7 wet days April: 11 wet days May: 13 wet days 13 June: 13 wet days July: 10 wet days August: 8 wet days September: 7 wet days October: 7 wet days November: 5 wet days December: 5 wet days 5 JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 53.7 in a year, most of it in March.

January: 5.3 in of snow February: 9.1 in of snow March: 10.4 in of snow 10.4 April: 10.0 in of snow May: 2.2 in of snow June: 0.1 in of snow July: 0.0 in of snow 0.0 August: 0.0 in of snow September: 0.1 in of snow October: 3.4 in of snow November: 6.5 in of snow December: 6.6 in of snow JFMAMJJASOND

How humid is Rapid City?

Muggy days peak in July, at about 1 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 0 muggy days July: 1 muggy days 1 August: 0 muggy days September: 0 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Rapid City Regional Airport, 9.1 mi ESE of the city center.

How much daylight?

Daylight ranges from about 8.9 hours in December to 15.4 hours in June.

January: 9.3 hours of daylight February: 10.5 hours of daylight March: 11.9 hours of daylight April: 13.5 hours of daylight May: 14.8 hours of daylight June: 15.4 hours of daylight 15.4 July: 15.1 hours of daylight August: 14.0 hours of daylight September: 12.5 hours of daylight October: 11.0 hours of daylight November: 9.7 hours of daylight December: 8.9 hours of daylight 8.9 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Rapid City, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 36°F13°F 0.3 in6 5.3 in 0 9.3 h
February 38°F14°F 0.5 in7 9.1 in 0 10.5 h
March 48°F23°F 0.9 in7 10.4 in 0 11.9 h
April 57°F31°F 2.1 in11 10.0 in 0 13.5 h
May 67°F42°F 3.5 in13 2.2 in 0 14.8 h
June 78°F52°F 2.9 in13 0.1 in 0 15.4 h
July 86°F59°F 2.3 in10 0.0 in 1 15.1 h
August 85°F56°F 1.6 in8 0.0 in 0 14.0 h
September 76°F46°F 1.2 in7 0.1 in 0 12.5 h
October 60°F34°F 1.4 in7 3.4 in 0 11.0 h
November 47°F22°F 0.5 in5 6.5 in 0 9.7 h
December 37°F14°F 0.3 in5 6.6 in 0 8.9 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Rapid City

By our comfort score, the best months are May and June.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 351117
Feb 381215
Mar 515210
Apr 60854
May 731571
Jun 721574
Jul 566512
Aug 556411
Sep 651235
Oct 591033
Nov 45429
Dec 341117

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Rapid City

The last spring frost typically comes around May 3, and the first fall frost around Oct 8, leaving 157 frost-free days in a typical year.

Frost and freeze dates for Rapid City
Typical date1 year in 10
Last spring frost (32°F)May 3after May 17
First fall frost (32°F)Oct 8before Sep 26
Last hard freeze (28°F)Apr 22after May 5
First hard freeze (28°F)Oct 18before Oct 3
Frost-free season157 daysunder 137 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Rapid City WFO (USC00396948), NOAA 1991-2020 freeze probabilities. Frost dates for every city in South Dakota.

Hottest and coldest readings, 1991-2020

The highest reading was 111°F (July 15, 2006); the lowest was -31°F (February 2, 1996).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Rapid City

Similar climates elsewhere

Where the numbers come from

  • Temperature and rain: Rapid City Rgnl Airport (USW00024090), 9.2 mi ESE of the city center, 3,160 ft (83 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Snowfall, snow depth and frost dates: Rapid City WFO (USC00396948), 1.1 mi ESE of the city center, 3,379 ft (136 ft higher than the city). NOAA normals and daily records, 1991-2020.
  • Humidity and wind by hour and cloud cover: Ellsworth AFB (USW00024006), 8.1 mi NE of the city center, 3,215 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Rapid City Regional Airport (726620-24090), 9.1 mi ESE of the city center, 3,162 ft (81 ft lower than the city). Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error