Belle Fourche, South Dakota climate: Normal weather by month, frost dates and records
Belle Fourche's normal year runs from 13°F January nights to 87°F July afternoons, with 18.0 inches of precipitation and 42 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.8°C, January lows of −11°C, July highs of 31°C, 457 mm of precipitation a year.
- NOAA stationBelle Fourche
- Station IDUSC00390559
- Location44.67°N 103.85°W
- Elevation3,020 ft (921 m)
- Population5,855
On October 23, the normal high in Belle Fourche is 58°F and the normal low 32°F, and the chance of measurable rain or snow is 22%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Belle Fourche.
- Jan 37° 13°
- Feb 39° 15°
- Mar 50° 24°
- Apr 59° 33°
- May 69° 44°
- Jun 79° 54°
- Jul 87° 60°
- Aug 87° 57°
- Sep 78° 47°
- Oct 62° 35°
- Nov 48° 24°
- Dec 37° 15°
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 Belle Fourche each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 13°F. The most precipitation falls in May (3.04 in), the least in January (0.44 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 37°F | 13°F | 24.7°F | 0.44 | 5.5 | 5 | <1 | 29 | 9 h 10 min |
| February | 39°F | 15°F | 27.1°F | 0.51 | 6.7 | 5 | <1 | 26 | 10 h 20 min |
| March | 50°F | 24°F | 36.8°F | 1.16 | 7.2 | 5 | <1 | 25 | 11 h 50 min |
| April | 59°F | 33°F | 45.9°F | 2.11 | 5.2 | 7 | <1 | 15 | 13 h 30 min |
| May | 69°F | 44°F | 56.0°F | 3.04 | 1.3 | 10 | 1 | 4 | 14 h 50 min |
| June | 79°F | 54°F | 66.5°F | 2.96 | 0.0 | 10 | 4 | <1 | 15 h 30 min |
| July | 87°F | 60°F | 73.5°F | 1.96 | 0.0 | 8 | 14 | <1 | 15 h 20 min |
| August | 87°F | 57°F | 71.7°F | 1.50 | 0.0 | 7 | 14 | <1 | 14 h 10 min |
| September | 78°F | 47°F | 62.2°F | 1.34 | 0.0 | 6 | 5 | 1 | 12 h 40 min |
| October | 62°F | 35°F | 48.6°F | 1.72 | 2.6 | 8 | <1 | 13 | 11 h |
| November | 48°F | 24°F | 35.6°F | 0.66 | 3.9 | 5 | <1 | 25 | 9 h 40 min |
| December | 37°F | 15°F | 26.0°F | 0.59 | 9.8 | 5 | <1 | 29 | 8 h 50 min |
| Year (annual) | 61°F | 35°F | 47.9°F | 17.99 | 42.2 | 80 | 38 | 167 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −11°C | −4.1°C | 11 mm | 14 cm |
| February | 4°C | −9°C | −2.7°C | 13 mm | 17 cm |
| March | 10°C | −5°C | 2.7°C | 29 mm | 18 cm |
| April | 15°C | 0°C | 7.7°C | 54 mm | 13 cm |
| May | 20°C | 6°C | 13.3°C | 77 mm | 3 cm |
| June | 26°C | 12°C | 19.2°C | 75 mm | 0 cm |
| July | 31°C | 15°C | 23.1°C | 50 mm | 0 cm |
| August | 30°C | 14°C | 22.1°C | 38 mm | 0 cm |
| September | 25°C | 8°C | 16.8°C | 34 mm | 0 cm |
| October | 17°C | 2°C | 9.2°C | 44 mm | 7 cm |
| November | 9°C | −5°C | 2.0°C | 17 mm | 10 cm |
| December | 3°C | −9°C | −3.3°C | 15 mm | 25 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00390559; 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 Belle Fourche?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (6).
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 USC00390559.
When is the last frost in Belle Fourche?
In Belle Fourche, the last spring frost (32°F) comes after May 10 in half of years and after May 25 in one year in ten; the first autumn frost comes before September 30 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 101 year in 10 after May 25; 9 in 10 after April 27
- First autumn frost, half of years before
- September 301 year in 10 before September 16; 9 in 10 before October 13
NOAA puts the median frost-free season at 143 days, and the season without a hard freeze (28°F) at 163 days.
A hard freeze (28°F) comes after April 30 in half of springs and before October 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Belle Fourche in zone 5b in ZIP code 57779, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Belle Fourche's NOAA station is in zone 4b: the coldest night of a typical year reaches −21°F (24 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 USC00390559; 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 Belle Fourche?
In a normal year in Belle Fourche, 38 days a year reach 90°F (4 of them 100°F or more), 167 nights fall to 32°F or colder and 80 days bring measurable precipitation.
- Days at 90°F or more
- 38a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 167a normal year
- Days that stay below freezing
- 39high of 32°F or less
- Days with 0.01 inch of precipitation
- 80a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1908) is 112°F, on July 27, 1931; the lowest is −44°F, on December 22, 1989.
The wettest calendar year on that record is 1946, with 25.41 in; the snowiest season is 1970–71, with 84.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00390559; records: ACIS (NOAA Regional Climate Centers), station USC00390559. Records use complete months only; a month missing more than three days is left out.
How sunny is Belle Fourche?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Belle Fourche, 4.3 kWh per square metre a day. July is the sunniest month (86%) and April the cloudiest (71%).
| 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 Belle Fourche need?
A normal year in Belle Fourche brings 6,902 heating degree days, 28% more than the median U.S. place (5,373), and 695 cooling degree days, 23% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,693 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,249 | 0 |
| February | 1,061 | 0 |
| March | 874 | 0 |
| April | 574 | 1 |
| May | 299 | 20 |
| June | 63 | 108 |
| July | 10 | 273 |
| August | 19 | 227 |
| September | 147 | 62 |
| October | 512 | 4 |
| November | 884 | 0 |
| December | 1,209 | 0 |
| Year (annual) | 6,902 | 695 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00390559. 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 Belle Fourche been warmer than normal lately?
2021 averaged 49.6°F, 1.7°F above the 1991-2020 normal of 47.9°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 49.6°F | +1.7°F | 13.71 | 27.7 |
Over 58 complete years from 1909 to 2021, the station's annual mean temperature rose at a fitted -0.2°F per century (−0.01°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00390559; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Belle Fourche's climate compare?
Belle Fourche is warmer than 87 of the other 99 places with their own NOAA record in South Dakota, and wetter than 12. Across the 7,247 U.S. stations with normals, its annual mean of 47.9°F is warmer than 31%.
In the Köppen classification computed from these normals, Belle Fourche is Dfa: continental, no dry season, hot summer. 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 Belle Fourche share this climate record?
Fruitdale has no NOAA station with 1991-2020 normals of its 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.
- Fruitdale, SD80 people · 8 mi E
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 Belle Fourche's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Belle Fourche. This page uses Belle Fourche; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Belle Fourche (22 mi NNW) USC00390565 | 22 mi N | 3,200 ft | 44.7°F | 9°F | 87°F | 14.7 | 37 | May 15 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Belle Fourche's climate
What is the coldest month in Belle Fourche?
January, with a normal high of 37°F and a normal low of 13°F. The warmest is July (87°F by day, 60°F at night).
Does it snow in Belle Fourche?
Yes: 42 inches in a normal year, falling on 18 days with 0.1 inch or more, the most in December (9.8 inches).
What is the rainiest month in Belle Fourche?
May, with 3.04 in of precipitation in a normal year; the driest is January with 0.44 in.
What plant hardiness zone is Belle Fourche in?
The USDA's 2023 map puts Belle Fourche in zone 5b in ZIP code 57779, the nearest ZIP area. By the same method at Belle Fourche's NOAA station, the coldest night of a typical year reaches −21°F (24 years, 1991-2020): zone 4b.
How late can frost come in Belle Fourche?
In half of years the last 32°F night comes after May 10; in one year in ten it comes after May 25. Waiting until May 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- South Dakota climateThe statewide normals and every place in the state
- Spearfish, SD12 miles from this station, 46.5°F a year
- Bear Ridge, SD15 miles from this station, 46.7°F a year
- Colony, WY21 miles from this station, 46.6°F a year
- Newell, SD21 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