Rapid City Rgnl, SD Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from Rapid City Rgnl's primary NOAA station, RAPID CITY RGNL AP.
The climate verdict for Rapid City Rgnl
Dryness leads the climate profile for Rapid City Rgnl, South Dakota, with 17.4 inches of precipitation a year. NOAA records an annual average of 47°F. At 49/100 (moderate) the climate comfort score falls in the bottom third of the station-mapped U.S. score corpus, exceeding only 18% of scores.
- 47°F
- yearly average temperature, NOAA normal
- 49/100
- comfort score, above 18% of station-mapped location scores
- 17.4"
- annual precipitation · 49" snow
- 142 days
- growing season, frost-free days
Rapid City Rgnl: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00024090 · Rapid City Rgnl, SD 47°F mean · 17.4" precip
TEMP-COOL · RANK-COOL · PHOTO-FINISH · PRCP-DRY · SWING-WIDE · COMF-LOW · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-COOL 47°F
- RANK-COOL #1,784
- PHOTO-FINISH ≈ Fort Duchesne
- PRCP-DRY 17.4"
- SWING-WIDE 48°F
- COMF-LOW 49/100
- LOAD-HEAT 7,252 HDD
- STN-1 USW00024090
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Fort Duchesne, UT (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every SD station list.
- Rapid City Rgnl (this station) 47°F
- Cold Brandenberg, MT 47°F
- Hot Forsyth, MT 47°F
- Near Fort Duchesne, UT 47°F
- Near Sullivan, WI 47°F
Climate Living Index · Rapid City Rgnl
Rapid City Rgnl: 37/100 · grade F
Rapid City Rgnl publishes all six Living Index dimensions from NOAA annual/seasonal normals · NOAA daily multivariate normals · NOAA hourly normals.
PlainClimate-derived for Rapid City Rgnl, not an official NOAA rating. Rankings still use Comfort Score 49/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Summer moisture balance | 52.4°F mean dew point | 98/100 · A |
| Precipitation balance | 17.4 in · 17.6 from 35 in | 37/100 · F |
| Annual temperature balance | 46.7°F · 20.8° from 67.5°F | 26/100 · F |
| Normal heat + freeze calendar | 183 calendar days | 23/100 · F |
| Snowfall burden | 48.5 inches/year | 22/100 · F |
| Frost-free season | 142 days/year | 20/100 · F |
Rapid City Rgnl · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Rapid City Rgnl's normals sit in a dry climate class: BSk
Precipitation is low relative to temperature but above true desert thresholds: cold semi-arid steppe (BSk). Class BSk is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: dry (arid or semi-arid), specifically cold semi-arid steppe.
- Köppen code
- BSk
- Group
- Dry (arid or semi-arid)
- Warmest month
- 72.4°F
- Coldest month
- 24.3°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Rapid City Rgnl sits across the climate record
Three NOAA fields for Rapid City Rgnl's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Cooler than 74%
- Among 6,861 stations, Rapid City Rgnl sits in the cooler third of annual means.
- Annual precipitation
- Drier than 77%
- Rapid City Rgnl's annual total ranks in the drier third of 6,352 measured normals.
- Seasonal temperature swing
- Wider than 74%
- Warmest-to-coldest month gap for Rapid City Rgnl is large versus 6,861 complete station-years.
How Rapid City Rgnl compares across U.S. station-mapped locations
Rapid City Rgnl's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
49 18th percentile score exceeds 18% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). This entry sits in this band.
- 50–60: 1,329 station-mapped locations (21%). Above this entry.
- 60–70: 1,236 station-mapped locations (20%). Above this entry.
- 70–80: 650 station-mapped locations (11%). Above this entry.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Rapid City Rgnl's measured station temperature trend
MethodologyAcross 122 complete annual observations from 1888 to 2025, RAPID CITY RGNL AP warmed at a fitted rate of 0.06°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Rapid City Rgnl primary station fitted change +0.06 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 36°F (2°C) | 13°F (-11°C) | 24°F (-4°C) | 0.3" | 5.3" | 30.3 | 0.0 |
| February | 38°F (3°C) | 14°F (-10°C) | 26°F (-3°C) | 0.5" | 7.7" | 26.7 | 0.0 |
| March | 48°F (9°C) | 23°F (-5°C) | 35°F (2°C) | 0.9" | 8.4" | 25.9 | 0.0 |
| April | 57°F (14°C) | 31°F (0°C) | 44°F (7°C) | 2.1" | 10.1" | 16.4 | 0.0 |
| May | 67°F (19°C) | 42°F (5°C) | 54°F (12°C) | 3.5" | 1.5" | 4.1 | 0.6 |
| June | 78°F (25°C) | 52°F (11°C) | 65°F (18°C) | 2.9" | 0.0" | 0.0 | 3.5 |
| July | 86°F (30°C) | 59°F (15°C) | 72°F (22°C) | 2.3" | 0.0" | 0.0 | 11.8 |
| August | 85°F (30°C) | 56°F (13°C) | 71°F (22°C) | 1.6" | 0.0" | 0.0 | 11.4 |
| September | 76°F (24°C) | 46°F (8°C) | 61°F (16°C) | 1.2" | 0.1" | 1.2 | 4.4 |
| October | 60°F (16°C) | 34°F (1°C) | 47°F (8°C) | 1.4" | 3.0" | 13.2 | 0.4 |
| November | 47°F (8°C) | 22°F (-6°C) | 35°F (1°C) | 0.5" | 5.7" | 26.3 | 0.0 |
| December | 37°F (3°C) | 14°F (-10°C) | 26°F (-4°C) | 0.3" | 6.7" | 30.3 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 88°F around July 24, short of 90°F on every date, while 183 dates carry a normal low at or below freezing, the coldest 13°F near January 1.
The freezing stretch
The normal low stays at or below 32°F into April 19, then returns to freezing around October 20, covering 183 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is June 1, when 44% of years recorded at least a hundredth of an inch. The driest is December 3 at 16%. Summed across the calendar, that is about 96 wet dates a year.
The widest day
September 6 carries the biggest normal gap between afternoon and dawn, 31°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Rapid City Rgnl.
Where Rapid City Rgnl Stands Nationally
Freezing is routine here by normals standards — the normal low reaches 32°F or colder on about 183 nights a year, more than most ranked stations.
Rapid City Rgnl earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 5.3"
5.7 days with precipitation
Snow: 7.7"
6.6 days with precipitation
Snow: 8.4"
7.0 days with precipitation
Snow: 10.1"
10.5 days with precipitation
Snow: 1.5"
12.6 days with precipitation
12.5 days with precipitation
9.8 days with precipitation
7.9 days with precipitation
Snow: 0.1"
6.6 days with precipitation
Snow: 3.0"
7.1 days with precipitation
Snow: 5.7"
5.1 days with precipitation
Snow: 6.7"
5.0 days with precipitation
Rapid City Rgnl runs a summer-peaked wet season
39% of Rapid City Rgnl's yearly precipitation falls in June, July and August alone, against the 25% an evenly spread year would give those three months. The wettest month is May at 3.5", on a wide 48.1°F gap between its warmest and coldest month. Warm-season convection and, across the Southwest, the North American monsoon produce this shape: rain arrives in short heavy bursts during the hottest part of the year rather than as long cool-season soaking.
- Wettest three months: May, June, July, taking 49% of the annual total between them.
- Driest month: January at 0.3".
- Winter share: 7% falls in December, January and February.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A summer-peaked label means the June-August share reaches 35%; it describes timing across an average year, not any single season, and says nothing about how heavy an individual storm can be.
Rapid City Rgnl is dry, and what does fall arrives gently
Only about 96 days a year record measurable precipitation here, 26% of the calendar, and they carry 17.4" between them. At roughly 0.18 inches on an average wet day, this is not the damp drizzle of a marine climate; it is an arid record in which precipitation is both uncommon and light when it appears.
The wettest month by count is May at about 13 wet days; the driest is December at about 5.
A low per-event average in a dry record is a statement about typical days only. Arid regions can still take a large share of a year's total from a single convective storm, which a normal cannot show.
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, not the extremes within it.
Winter brings real snow to Rapid City Rgnl
Rapid City Rgnl averages 48.5 inches of snowfall a year, with April the snowiest month on the normals, spread across roughly 33 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 48.5 inches of depth.
- Days recording measurable snow: about 33 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 28% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
October 1
50% probability date
Last Spring Freeze
May 12
50% probability date
Growing Season
142 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
7,252
Higher = more heating needed
Cooling Degree Days
607
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Humidity & Wind
Monthly averages from hourly observations
| Month | Humidity | Wind (mph) | Clear Sky % | Overcast % |
|---|---|---|---|---|
| January | 64% | 10.3 | 53% | 26% |
| February | 64% | 10.9 | 54% | 26% |
| March | 58% | 12.2 | 49% | 28% |
| April | 58% | 12.2 | 50% | 26% |
| May | 65% | 10.5 | 52% | 22% |
| June | 59% | 9.7 | 66% | 9% |
| July | 56% | 8.9 | 70% | 8% |
| August | 51% | 9.5 | 75% | 9% |
| September | 54% | 10.3 | 67% | 17% |
| October | 58% | 10.8 | 61% | 23% |
| November | 63% | 10.2 | 62% | 23% |
| December | 66% | 9.7 | 58% | 24% |
Nationwide similar cities
Other rankable U.S. places outside SD closest to Rapid City Rgnl on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (47°F here).
- Allison, IA 47°F · 0.0°F off
- American Falls, ID 47°F · 0.0°F off
- Cherokee, IA 47°F · 0.0°F off
- Forsyth, MT 47°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (17.4" here), excluding temperature-peer places.
- Riggins, ID 17.4" · 0.0" off
- Medora, ND 17.4" · 0.0" off
- Estes Park, CO 17.4" · 0.0" off
- Fort Bidwell, CA 17.5" · 0.0" off
Snow and freeze rhythm
When cold and snow define Rapid City Rgnl
heating led · dry · mid swing
Rapid City Rgnl's energy balance leans toward cold weather: 7,252 annual heating degree days against 607 for cooling. Its 48.1°F seasonal range still makes the monthly rows more useful than the annual average alone.
Only about 142 days are frost-free in a normal year. That short interval is consistent with the cold-season signal, but the measure does not predict the exact first or last freeze in any one year.
-
1. Rapid City Rgnl coldest normal
January
Averaging 24°F (-4°C), this month sits below freezing for the month as a whole, not merely overnight.
-
2. Rapid City Rgnl typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. Rapid City Rgnl snow peak
April
Rapid City Rgnl averages 48.5 inches of snow a year, with April the snowiest month on the normals.
Questions about Rapid City Rgnl's climate
How much snow does Rapid City Rgnl get? ▼
How many days above 90°F does Rapid City Rgnl get? ▼
How much energy does heating and cooling require in Rapid City Rgnl? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Rapid City Rgnl's primary station: RAPID CITY RGNL AP (USW00024090). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The conservative exact name-and-state crosswalk finds no Census place match, so PlainClimate treats this as a station-mapped location and does not claim it is a municipality. No exact Gazetteer row for Rapid City Rgnl; facility counts that depend on place identity are therefore an upper bound, not a municipal census.
On this page every temperature, precipitation, and derived score for Rapid City Rgnl comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.