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Average Weather in Belle Fourche South Dakota, United States

In Belle Fourche, the summers are short, warm, and mostly clear and the winters are long, freezing, dry, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 19°F to 88°F and is rarely below -2°F or above 98°F.

Based on the tourism score, the best time of year to visit Belle Fourche for warm-weather activities is from late June to late August.

Climate Summary

very coldcoldcoolwarmhotwarmcoolcoldvery coldJanFebMarAprMayJunJulAugSepOctNovDecNowNow77%77%46%46%clearovercastprecipitation: 2.5 inprecipitation: 2.5 in0.1 in0.1 inmuggy: 3%muggy: 3%0%0%drydrytourism score: 7.1tourism score: 7.10.10.1
Click on each chart for more information.

Temperature

The hot season lasts for 2.9 months, from June 14 to September 10, with an average daily high temperature above 78°F. The hottest day of the year is July 26, with an average high of 88°F and low of 62°F.

The cold season lasts for 3.8 months, from November 17 to March 11, with an average daily high temperature below 47°F. The coldest day of the year is December 31, with an average low of 19°F and high of 37°F.

Average High and Low Temperature

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.

Average Hourly Temperature

Average Hourly Temperature in Belle FourcheJanFebMarAprMayJunJulAugSepOctNovDec12 AM4 AM8 AM12 PM4 PM8 PM12 AMNowNowfreezingfreezingfreezingfreezingvery coldvery coldcoldcoldcoolcomfortablewarmcomfortable
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Kuluncak, Turkey (6,194 miles away) is the far-away foreign place with temperatures most similar to Belle Fourche (view comparison).

Clouds

In Belle Fourche, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.

The clearer part of the year in Belle Fourche begins around June 7 and lasts for 4.0 months, ending around October 7. On July 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 77% of the time, and overcast or mostly cloudy 23% of the time.

The cloudier part of the year begins around October 7 and lasts for 8.0 months, ending around June 7. On March 14, the cloudiest day of the year, the sky is overcast or mostly cloudy 54% of the time, and clear, mostly clear, or partly cloudy 46% of the time.

Cloud Cover Categories

Cloud Cover Categories in Belle FourcheclearercloudiercloudierJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Jul 2377%Jul 2377%Mar 1446%Mar 1446%Jun 761%Jun 761%Oct 762%Oct 762%NowNowclearmostly clearpartly cloudymostly cloudyovercast
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Belle Fourche varies significantly throughout the year.

The wetter season lasts 4.1 months, from April 15 to August 18, with a greater than 19% chance of a given day being a wet day. The chance of a wet day peaks at 35% on June 4.

The drier season lasts 7.9 months, from August 18 to April 15. The smallest chance of a wet day is 3% on January 15.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Belle Fourche changes throughout the year.

Rain alone is the most common for 9.0 months, from February 1 to February 10 and from February 27 to November 19. The highest chance of a day with rain alone is 35% on June 4.

Snow alone is the most common for 3.0 months, from February 10 to February 27 and from November 19 to February 1. The highest chance of a day with snow alone is 3% on February 23.

Daily Chance of Precipitation

Daily Chance of Precipitation in Belle FourchesnowrainsnowJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jun 435%Jun 435%Jan 153%Jan 153%Feb 277%Feb 277%Nov 196%Nov 196%Apr 1519%Apr 1519%Aug 1819%Aug 1819%NowNowrainsnow
The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Belle Fourche experiences significant seasonal variation in monthly rainfall.

The rainy period of the year lasts for 7.4 months, from March 21 to November 2, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around May 25, with an average total accumulation of 2.5 inches.

The rainless period of the year lasts for 4.6 months, from November 2 to March 21. The least rain falls around January 17, with an average total accumulation of 0.1 inches.

Average Monthly Rainfall

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Snowfall

The sliding 31-day liquid-equivalent quantity of snowfall in Belle Fourche does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.

Average Liquid-Equivalent Monthly Snowfall

Average Liquid-Equivalent Monthly Snowfall in Belle FourchesnowsnowJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.5 in1.0 in1.5 in2.0 in2.5 inMar 230.2 inMar 230.2 inJul 190.0 inJul 190.0 inDec 10.1 inDec 10.1 inMay 10.1 inMay 10.1 in
The average liquid-equivalent snowfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average rainfall.

Sun

The length of the day in Belle Fourche varies significantly over the course of the year. In 2020, the shortest day is December 21, with 8 hours, 48 minutes of daylight; the longest day is June 20, with 15 hours, 35 minutes of daylight.

Hours of Daylight and Twilight

Hours of Daylight and Twilight in Belle FourcheJanFebMarAprMayJunJulAugSepOctNovDec0 hr24 hr4 hr20 hr8 hr16 hr12 hr12 hr16 hr8 hr20 hr4 hr24 hr0 hr12 hr, 8 minMar 1912 hr, 8 minMar 1915 hr, 35 minJun 2015 hr, 35 minJun 2012 hr, 12 minSep 2212 hr, 12 minSep 228 hr, 48 minDec 218 hr, 48 minDec 21nightnightdayNowNow
The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The earliest sunrise is at 5:09 AM on June 15, and the latest sunrise is 2 hours, 23 minutes later at 7:32 AM on October 31. The earliest sunset is at 4:14 PM on December 9, and the latest sunset is 4 hours, 30 minutes later at 8:44 PM on June 26.

Daylight saving time (DST) is observed in Belle Fourche during 2020, starting in the spring on March 8, lasting 7.8 months, and ending in the fall on November 1.

Sunrise & Sunset with Twilight and Daylight Saving Time

Sunrise & Sunset with Twilight and Daylight Saving Time in Belle FourcheJanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AMJun 155:09 AMJun 155:09 AM8:44 PMJun 268:44 PMJun 26Dec 94:14 PMDec 94:14 PM7:32 AMOct 317:32 AMOct 31Mar 8DSTMar 8DSTDSTNov 1DSTNov 1daynightnightnightnightSolarMidnightSolarMidnightSolarNoonSunriseSunsetNowNow
The solar day over the course of the year 2020. From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray. The transitions to and from daylight saving time are indicated by the 'DST' labels.

Humidity

We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.

The perceived humidity level in Belle Fourche, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 1% of 1% throughout.

Humidity Comfort Levels

Humidity Comfort Levels in Belle FourcheJanFebMarAprMayJunJulAugSepOctNovDec0%10%20%30%40%50%60%70%80%90%100%Jan 140%Jan 140%Jul 213%Jul 213%NowNowdrydrycomfortablecomfortablehumidhumid
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The percentage of time spent at various humidity comfort levels, categorized by dew point.

Wind

This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.

The average hourly wind speed in Belle Fourche experiences significant seasonal variation over the course of the year.

The windier part of the year lasts for 7.6 months, from October 1 to May 20, with average wind speeds of more than 9.1 miles per hour. The windiest day of the year is January 18, with an average hourly wind speed of 10.8 miles per hour.

The calmer time of year lasts for 4.4 months, from May 20 to October 1. The calmest day of the year is July 29, with an average hourly wind speed of 7.4 miles per hour.

Average Wind Speed

Average Wind Speed in Belle FourchewindywindyJanFebMarAprMayJunJulAugSepOctNovDec0 mph2 mph4 mph6 mph8 mph10 mph12 mph14 mph16 mphJan 1810.8 mphJan 1810.8 mphJul 297.4 mphJul 297.4 mphOct 19.1 mphOct 19.1 mphMay 209.1 mphMay 209.1 mphNowNow
The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.

The predominant average hourly wind direction in Belle Fourche varies throughout the year.

The wind is most often from the south for 2.4 months, from June 22 to September 4, with a peak percentage of 32% on August 20. The wind is most often from the west for 9.6 months, from September 4 to June 22, with a peak percentage of 66% on January 1.

Wind Direction

Wind Direction in Belle FourcheWSWJanFebMarAprMayJunJulAugSepOctNovDec0%100%20%80%40%60%60%40%80%20%100%0%NowNowwestsouthnortheast
northeastsouthwest
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions, excluding hours in which the mean wind speed is less than 1.0 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Best Time of Year to Visit

To characterize how pleasant the weather is in Belle Fourche throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Belle Fourche for general outdoor tourist activities is from late June to late August, with a peak score in the last week of July.

Tourism Score

Tourism Score in Belle Fourchebest timeJanFebMarAprMayJunJulAugSepOctNovDec02468107.17.10.10.1NowNow precipitationprecipitationcloudscloudstemperaturetemperaturetourism score
The tourism score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Belle Fourche for hot-weather activities is from early July to mid August, with a peak score in the last week of July.

Beach/Pool Score

Beach/Pool Score in Belle FourcheJanFebMarAprMayJunJulAugSepOctNovDec02468105.25.20.00.0NowNow precipitationprecipitationcloudscloudstemperaturetemperaturebeach/pool score
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Growing Season

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in Belle Fourche typically lasts for 5.3 months (161 days), from around April 29 to around October 7, rarely starting before April 9 or after May 19, and rarely ending before September 14 or after October 29.

Time Spent in Various Temperature Bands and the Growing Season

Time Spent in Various Temperature Bands and the Growing Season in Belle Fourchegrowing seasonJanFebMarAprMayJunJulAugSepOctNovDec0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%Apr 2950%Apr 2950%Oct 750%Oct 750%May 1990%May 1990%Sep 1490%Sep 1490%Apr 910%Apr 910%Oct 2910%Oct 2910%0%Feb 130%Feb 13Jul 17100%Jul 17100%NowNowfreezingvery coldcoolcomfortablewarmhotcold
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The percentage of time spent in various temperature bands. The black line is the percentage chance that a given day is within the growing season.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in Belle Fourche should appear around April 12, only rarely appearing before March 26 or after April 28.

Growing Degree Days

The average growing degree days accumulated over the course of the year, with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.

The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.

The brighter period of the year lasts for 3.2 months, from May 10 to August 16, with an average daily incident shortwave energy per square meter above 6.5 kWh. The brightest day of the year is July 2, with an average of 7.8 kWh.

The darker period of the year lasts for 3.5 months, from October 28 to February 13, with an average daily incident shortwave energy per square meter below 2.9 kWh. The darkest day of the year is December 24, with an average of 1.7 kWh.

Average Daily Incident Shortwave Solar Energy

Average Daily Incident Shortwave Solar Energy in Belle FourchebrightdarkdarkJanFebMarAprMayJunJulAugSepOctNovDec0 kWh1 kWh2 kWh3 kWh4 kWh5 kWh6 kWh7 kWh8 kWh9 kWhJul 27.8 kWhJul 27.8 kWhDec 241.7 kWhDec 241.7 kWhMay 106.5 kWhMay 106.5 kWhAug 166.5 kWhAug 166.5 kWhOct 282.9 kWhOct 282.9 kWhFeb 132.9 kWhFeb 132.9 kWhNowNow
The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

For the purposes of this report, the geographical coordinates of Belle Fourche are 44.671 deg latitude, -103.852 deg longitude, and 3,081 ft elevation.

The topography within 2 miles of Belle Fourche contains only modest variations in elevation, with a maximum elevation change of 243 feet and an average elevation above sea level of 3,067 feet. Within 10 miles contains only modest variations in elevation (1,204 feet). Within 50 miles contains very significant variations in elevation (4,757 feet).

The area within 2 miles of Belle Fourche is covered by grassland (78%) and cropland (16%), within 10 miles by grassland (87%), and within 50 miles by grassland (65%) and trees (18%).

Data Sources

This report illustrates the typical weather in Belle Fourche, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

Temperature and Dew Point

There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Belle Fourche.

For each station, the records are corrected for the elevation difference between that station and Belle Fourche according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.

The estimated value at Belle Fourche is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Belle Fourche and a given station.

The stations contributing to this reconstruction are: Black Hills Airport (72%, 22 kilometers, south); Buffalo (13%, 107 kilometers, north); Gillette-Campbell County Airport (8%, 139 kilometers, west); and Faith (8%, 150 kilometers, east).

Other Data

All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.

All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.

Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.

Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.

Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .

Time zones for aiports and weather stations are provided by AskGeo.com .

Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.