Rapid City, South Dakota climate: Normal weather by month, frost dates and records
Rapid City's normal year runs from 13°F January nights to 86°F July afternoons, with 17.4 inches of precipitation and 49 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.2°C, January lows of −11°C, July highs of 30°C, 443 mm of precipitation a year.
- NOAA stationRapid City Regional Airport
- Station IDUSW00024090
- Location44.04°N 103.05°W
- Elevation3,160 ft (963 m)
- Population79,894
On October 23, the normal high in Rapid City is 57°F and the normal low 31°F, and the chance of measurable rain or snow is 21%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Rapid City.
- Jan 36° 13°
- Feb 38° 14°
- Mar 48° 23°
- Apr 57° 31°
- May 67° 42°
- Jun 78° 52°
- Jul 86° 59°
- Aug 85° 56°
- Sep 76° 46°
- Oct 60° 34°
- Nov 47° 22°
- Dec 37° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Rapid City each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 13°F. The most precipitation falls in May (3.45 in), the least in January (0.31 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 36°F | 13°F | 24.3°F | 0.31 | 5.3 | 6 | <1 | 30 | 9 h 10 min |
| February | 38°F | 14°F | 26.1°F | 0.50 | 7.7 | 7 | <1 | 27 | 10 h 30 min |
| March | 48°F | 23°F | 35.4°F | 0.91 | 8.4 | 7 | <1 | 26 | 11 h 50 min |
| April | 57°F | 31°F | 43.9°F | 2.08 | 10.1 | 11 | <1 | 16 | 13 h 20 min |
| May | 67°F | 42°F | 54.1°F | 3.45 | 1.5 | 13 | 1 | 4 | 14 h 40 min |
| June | 78°F | 52°F | 64.6°F | 2.87 | 0.0 | 13 | 4 | <1 | 15 h 30 min |
| July | 86°F | 59°F | 72.4°F | 2.28 | 0.0 | 10 | 12 | <1 | 15 h 10 min |
| August | 85°F | 56°F | 70.8°F | 1.59 | 0.0 | 8 | 11 | <1 | 14 h |
| September | 76°F | 46°F | 61.3°F | 1.22 | 0.1 | 7 | 4 | 1 | 12 h 40 min |
| October | 60°F | 34°F | 47.1°F | 1.41 | 3.0 | 7 | <1 | 13 | 11 h 10 min |
| November | 47°F | 22°F | 34.6°F | 0.47 | 5.7 | 5 | <1 | 26 | 9 h 40 min |
| December | 37°F | 14°F | 25.6°F | 0.35 | 6.7 | 5 | <1 | 30 | 8 h 50 min |
| Year (annual) | 60°F | 34°F | 46.7°F | 17.44 | 48.5 | 96 | 32 | 174 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −11°C | −4.3°C | 8 mm | 13 cm |
| February | 3°C | −10°C | −3.3°C | 13 mm | 20 cm |
| March | 9°C | −5°C | 1.9°C | 23 mm | 21 cm |
| April | 14°C | 0°C | 6.6°C | 53 mm | 26 cm |
| May | 19°C | 5°C | 12.3°C | 88 mm | 4 cm |
| June | 25°C | 11°C | 18.1°C | 73 mm | 0 cm |
| July | 30°C | 15°C | 22.4°C | 58 mm | 0 cm |
| August | 30°C | 13°C | 21.6°C | 40 mm | 0 cm |
| September | 24°C | 8°C | 16.3°C | 31 mm | 0 cm |
| October | 16°C | 1°C | 8.4°C | 36 mm | 8 cm |
| November | 8°C | −6°C | 1.4°C | 12 mm | 14 cm |
| December | 3°C | −10°C | −3.6°C | 9 mm | 17 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024090; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Rapid City?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (7).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024090.
When is the last frost in Rapid City?
In Rapid City, the last spring frost (32°F) comes after May 12 in half of years and after May 26 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 16 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 121 year in 10 after May 26; 9 in 10 after May 1
- First autumn frost, half of years before
- October 11 year in 10 before September 16; 9 in 10 before October 14
NOAA puts the median frost-free season at 139 days, and the season without a hard freeze (28°F) at 159 days.
A hard freeze (28°F) comes after May 2 in half of springs and before October 9 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Rapid City in zone 5b in ZIP code 57701. By the map's own method, the average of each year's coldest night over 1991-2020, Rapid City's NOAA station is in zone 5a: the coldest night of a typical year reaches −17°F (30 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in South Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00024090; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Rapid City?
In a normal year in Rapid City, 32 days a year reach 90°F (5 of them 100°F or more), 174 nights fall to 32°F or colder and 96 days bring measurable precipitation.
- Days at 90°F or more
- 32a normal year
- Days at 100°F or more
- 5a normal year
- Nights at 32°F or colder
- 174a normal year
- Days that stay below freezing
- 43high of 32°F or less
- Days with 0.01 inch of precipitation
- 96a normal year
- Days with 1 inch of snow or more
- 15a normal year
The highest temperature in Rapid City's official record (kept by the National Weather Service since 1942) is 112°F, on July 25, 2026; the lowest is −31°F, on February 2, 1996.
The wettest calendar year on that record is 2019, with 28.43 in; the snowiest season is 1985–86, with 80.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00024090; records: ACIS (NOAA Regional Climate Centers), NWS threaded record RAPthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Rapid City, and how clear are its skies?
The summer (June-August) dew point averages 52°F. The muggiest month is July, with an average dew point of 55°F; the driest air comes in December (13°F). April is the windiest month (12.2 mph on average), and August has the most clear or nearly clear hours (82%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 15°F | 64% | 48% | 10.3 mph | 61% | 26% |
| February | 17°F | 64% | 46% | 10.9 mph | 61% | 26% |
| March | 26°F | 58% | 39% | 12.2 mph | 57% | 28% |
| April | 34°F | 58% | 40% | 12.2 mph | 58% | 26% |
| May | 48°F | 65% | 48% | 10.5 mph | 61% | 22% |
| June | 54°F | 59% | 40% | 9.7 mph | 77% | 9% |
| July | 55°F | 56% | 36% | 8.9 mph | 79% | 8% |
| August | 49°F | 51% | 30% | 9.5 mph | 82% | 9% |
| September | 37°F | 54% | 33% | 10.3 mph | 73% | 17% |
| October | 26°F | 58% | 39% | 10.8 mph | 66% | 23% |
| November | 18°F | 63% | 48% | 10.2 mph | 68% | 23% |
| December | 13°F | 66% | 54% | 9.7 mph | 66% | 24% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024090. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Rapid City?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Rapid City, 4.3 kWh per square metre a day. July is the sunniest month (86%) and April the cloudiest (71%). Among the 459 U.S. places of 50,000 or more, that ranks tied 210th (with 32 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 1.9 |
| February | 76% | 2.9 |
| March | 74% | 4.0 |
| April | 71% | 5.0 |
| May | 72% | 5.9 |
| June | 80% | 6.8 |
| July | 86% | 7.0 |
| August | 86% | 6.0 |
| September | 82% | 4.7 |
| October | 75% | 3.1 |
| November | 75% | 2.1 |
| December | 72% | 1.6 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Rapid City need?
A normal year in Rapid City brings 7,252 heating degree days, 35% more than the median U.S. place (5,373), and 607 cooling degree days, 33% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,482 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,260 | 0 |
| February | 1,091 | 0 |
| March | 918 | 0 |
| April | 634 | 1 |
| May | 349 | 11 |
| June | 93 | 81 |
| July | 13 | 244 |
| August | 25 | 205 |
| September | 175 | 62 |
| October | 560 | 3 |
| November | 912 | 0 |
| December | 1,223 | 0 |
| Year (annual) | 7,252 | 607 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024090. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has Rapid City been warmer than normal lately?
2025 averaged 49.4°F, 2.6°F above the 1991-2020 normal of 46.7°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 48.2°F | +1.5°F | 16.37 | – |
| 2022 | 46.3°F | −0.4°F | 16.10 | – |
| 2023 | 47.6°F | +0.9°F | 19.63 | – |
| 2024 | 50.3°F | +3.6°F | 13.34 | – |
| 2025 | 49.4°F | +2.6°F | 18.11 | – |
Over 122 complete years from 1888 to 2025, the station's annual mean temperature rose at a fitted 1.1°F per century (+0.06°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00024090; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Rapid City's climate compare?
Rapid City is warmer than 67 of the other 99 places with their own NOAA record in South Dakota, and wetter than 8. Across the 7,247 U.S. stations with normals, its annual mean of 46.7°F is warmer than 26%.
In the Köppen classification computed from these normals, Rapid City is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Rapid City share this climate record?
6 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Box Elder, SD13,887 people · 5 mi N
- Rapid Valley, SD7,153 people · 4 mi NW
- Green Valley, SD1,503 people · 3 mi W
- Ashland Heights, SD1,142 people · 7 mi NW
- New Underwood, SD610 people · 11 mi E
- Caputa, SD29 people · 5 mi SE
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Rapid City's other NOAA stations record?
2 more NOAA stations keep 1991-2020 normals in or near Rapid City. This page uses Rapid City Regional Airport; the others differ by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Rapid City (4 mi NW) USC00396947 | 13 mi NW | 3,479 ft | 46.3°F | 13°F | 84°F | 18.8 | 36 | May 10 |
| Rapid City Weather Office USC00396948 | 8 mi W | 3,379 ft | 48.0°F | 16°F | 84°F | 20.0 | 54 | May 3 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Rapid City's climate
What is the coldest month in Rapid City?
January, with a normal high of 36°F and a normal low of 13°F. The warmest is July (86°F by day, 59°F at night).
Does it snow in Rapid City?
Yes: 49 inches in a normal year, falling on 33 days with 0.1 inch or more, the most in April (10.1 inches).
What is the rainiest month in Rapid City?
May, with 3.45 in of precipitation in a normal year; the driest is January with 0.31 in.
What plant hardiness zone is Rapid City in?
The USDA's 2023 map puts Rapid City in zone 5b in ZIP code 57701. By the same method at Rapid City's NOAA station, the coldest night of a typical year reaches −17°F (30 years, 1991-2020): zone 5a.
How late can frost come in Rapid City?
In half of years the last 32°F night comes after May 12; in one year in ten it comes after May 26. Waiting until May 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Rapid City in OctoberThis month day by day, its records and recent years
- South Dakota climateThe statewide normals and every place in the state
- Johnson Siding, SD19 miles from this station, 45.1°F a year
- Hereford (12 mi SW), SD20 miles from this station, 46.9°F a year
- Pactola Dam, SD21 miles from this station, 42.1°F a year
- Mount Rushmore National Memorial, SD23 miles from this station, 45.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made