Climate and monthly weather forecast
Rapid City, SD

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A scenic panorama of the Rapid City in South Dakota
A scenic panorama of the Rapid City in South Dakota

The climate of Rapid City

Rapid City, South Dakota lies within the Dfa Köppen climate zone, predominantly characterized by a humid continental climate, without a dry season and with hot summers. The geographical placement of Rapid City contributes to the varied weather conditions throughout the year.

Examining available climatological data, a significant variation in temperature exists throughout the year. High temperatures range from a brisk 32.5°F (0.3°C) in December to a warm 84.7°F (29.3°C) in July. Low temperatures similarly fluctuate, registering at 18°F (-7.8°C) in January and ascending to 63.3°F (17.4°C) in July. Concurrently, relative humidity remains generally moderate to high, peaking at 77% in January and dipping to its lowest at 50% between July and September.

Precipitation patterns reveal insightful details about Rapid City's climate. Monthly average rainfall amounts range from a relatively low 0.43" (11mm) in January to a substantial 2.28" (58mm) in May. Rainfall days per month vary from approximately five days in winter months to a high of 17.1 days in May. Moreover, while snowfall primarily occurs from December to April peak at 5.43" (138mm) in April, traces can be found as late as May and as early as October. The amount of daylight and sunshine hours fluctuate according to the season, with the maximum daylight of 15.4 hours in June and minimum of 8.9 hours in December.

The best time to visit Rapid City

Given the multiple facets of Rapid City's climate, the best time to visit largely depends on the activities one desires to partake in. Travelers seeking warmer weather and longer days should consider visiting between May and September. During this period, average high temperatures range from 63.1°F (17.3°C) to 84.7°F (29.3°C), whilst average low temperatures span from 45.3°F (7.4°C) to 63.3°F (17.4°C). June provides the most daylight with approximately 15.4 hours per day, henceforth providing ample time for outdoor explorations. Sunshine levels peak in July with an average of 11.7 hours a day.

The worst time to visit Rapid City

Conversely, the worst time to visit Rapid City, particularly for travelers averse to cold weather, would be from December to February. During these months, average high temperatures fluctuate between 32.5°F (0.3°C) and 33.4°F (0.8°C), whereas low temperatures fluctuate between 18°F (-7.8°C) and 17.8°F (-7.9°C). Both daylight and sunshine hours decrease significantly during this period, with the shortest daylight hours seen in December at a mere 8.9 hours and the lowest sunshine hours observed in February with 5.9 hours a day.

Spring weather in Rapid City

Springtime in Rapid City can be characterized by warming temperatures, increased rainfall, and expanding daylight hours. From March to May, average high temperatures increase from 45.5°F (7.5°C) to 63.1°F (17.3°C), whereas average low temperatures rise from 28.8°F (-1.8°C) to 45.3°F (7.4°C). Concurrently, rainfall escalates from 1.14" (29mm) in March to a peak of 2.28" (58mm) in May. Days of rainfall also follow this trend with a significant increase from 9.4 days in March to 17.1 days in May.

Summer weather in Rapid City

Summer in Rapid City is marked by the warmest temperatures, longest days, and relatively reduced rainfall. From June to August, average high temperatures oscillate between 76.5°F (24.7°C) and 84.7°F (29.3°C), and average low temperatures from 55.9°F (13.3°C) to 63.3°F (17.4°C). Rainfall decreases from 1.73" (44mm) in June to 1.5" (38mm) in August whereas the number of rainy days remains relatively stable, hovering just below 14 days per month.

Autumn weather in Rapid City

Autumn ushers in a gradual decrease in temperatures, reduction in hours of daylight and sunshine, and a decrease in precipitation. From September to November, average high temperatures fall from 73.9°F (23.3°C) to 45.1°F (7.3°C), while average low temperatures tumble from 54°F (12.2°C) to 29.1°F (-1.6°C). Rainfall levels drop from 0.94" (24mm) in September to 0.63" (16mm) in November, with the number of rainy days decreasing from nearly eight in September to nearly six in November.

Winter weather in Rapid City

Winter in Rapid City is characterized by cold temperatures, relatively low precipitation, and shortest daylight hours. Throughout December to February, average high temperatures range from 32.5°F (0.3°C) to 33.4°F (0.8°C), while average low temperatures shift between 18°F (-7.8°C) and 17.8°F (-7.9°C). Rainfall is at its lowest, reporting 0.63" (16mm) in both December and January. Average snowfall peaks at 2.64" (67mm) in December, with an average of nine snowy days in a month.

Weather in January

Cold weather persists in January, making it integral for residents and tourists in Rapid City, South Dakota to layer up. Some of the coldest temperatures of the year occur during this month with a chilling low at around 18°F (-7.8°C). Weather in January »

Weather in February

Gradual temperature changes occur in Rapid City heading into February, following the January chill. Snow continues to grace the city, but the total snowfall decreases slightly compared to the previous month. An extra hour of daylight is welcomed, heralding the slow approach of spring. Weather in February »

Weather in March

The arrival of March ushers in subtle signs of spring in Rapid City. The days become noticeably longer, and temperatures start to climb, mirroring the seasonal transition. Snowfall starts to dwindle with highest temperature now sitting comfortably at 45.5°F (7.5°C). Weather in March »

Weather in April

April brings with it more rainfall than March—registering at approximately 2.24" (57mm). It marks the onset of the wet season in Rapid City. Temperature highs continue to climb, reaching into the 50s°F, much to the relief of residents. Weather in April »

Weather in May

May manifests classic spring weather features in Rapid City. Residents begin to appreciate the warmer temperatures, extended daylight hours, and the beautiful blossoming flora associated with spring. Average rainfall during this time is 2.28" (58mm), with daylight spanning for an impressive 14.8 hours. Weather in May »

Weather in June

Rapid City ushers in summer with June’s consistent warmth. The longer daylight hours persist, presenting an ideal time for outdoor activities. When compared to May, June brings fewer rainy days, and the city welcomes a decrease in humidity. Weather in June »

Weather in July

July is the quintessential summer month in Rapid City. With an average high of 84.7°F (29.3°C), this is the hottest month of the year. Days see more sunshine than any other month, ensuring a true summer experience. Snowfall naturally becomes nonexistent, while daylight hours peak at the zenith of summer. Weather in July »

Weather in August

August continues the summer trend in Rapid City, South Dakota. Although temperatures start to cool down a notch, the heat persists, keeping the ambiance summery. It's one of the months with the least cloud cover, maximizing visibility, and promoting extended hours of sunshine. Weather in August »

Weather in September

Even though September ushers in autumn, the weather may still feel summery, especially at the month's onset. However, this month has a notorious reputation for a sharp decrease in temperature, signalling the end of summer. Rapid City experiences a significant reduction in rainfall from 1.5" (38mm) in August to 0.94" (24mm). Weather in September »

Weather in October

October further amplifies the autumn vibe in Rapid City, carrying in a cooler scent of the air. Dipping temperatures give rise to warm-layer dressing, and the first signs of snow appear, hinting at winter's proximity. A slight increase in rainfall accompanies the weather shift. Weather in October »

Weather in November

November translates into colder weather in Rapid City. The shift towards winter becomes even clearer as daylight hours continue to reduce. Snowfall becomes more frequent, blanketing the city with an average of 2.4" (61mm). Likewise, a hike in relative humidity sets a damper atmosphere. Weather in November »

Weather in December

December in Rapid City, South Dakota culminates in full-blown winter weather. An average temperature low at around 18.7°F (-7.4°C) suggests the harshness of the season. Snowfall, combined with a decrease in daylight hours, creates quintessential cozy winter days. Weather in December »
Updated: Aug 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the most humid month?

The most humid month is January, with an average relative humidity of 77%.

What is the driest month?

January is the month with the least rainfall. Rain falls for 5.3 days and accumulates 0.43" (11mm) of precipitation.

How much does it rain?

Throughout the year, there are 118.8 rainfall days, and 15.39" (391mm) of precipitation is accumulated.

When does it snow?

Months with snowfall are January through May, September through December.

How much does it snow?

Throughout the year, there are 50.4 snowfall days, and 24.41" (620mm) of snow is accumulated.

What are the months with the lowest UV index?

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

What is the month with the least sunshine?

The month with the least sunshine is February, with an average of 5.9h of sunshine.

When is Daylight Saving Time (DST)?

On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from MST to MDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from MDT to MST.

What is the snowiest month?

The month with the most snowfall is April, when snow falls for 5.3 days and typically aggregates up to 5.43" (138mm) of snow.

What is the wettest month?

The month with the most rainfall is May, when the rain falls for 17.1 days and typically aggregates up to 2.28" (58mm) of precipitation.

When it does not snow?

In Rapid City, snow does not fall in June through August.

When are the longest days?

With an average of 15h and 24min of daylight, June has the longest days of the year.

What is the month with the highest UV index?

The months with the highest UV index are June and July, with an average maximum UV index of 6.

What is the warmest month?

Rapid City notes the warmest temperatures in July, with a average high of 84.7°F (29.3°C) and a low of 63.3°F (17.4°C).

What are the least humid months?

The months with the lowest humidity are August and September, with an average relative humidity of 50%.

What month has the most sunshine?

With an average of 11.8h of sunshine, August has the most sunshine of the year.

What month is the coldest?

The month of December sees the average lowest temperatures in Rapid City, reaching 32.5°F (0.3°C) at the peak and 18.7°F (-7.4°C) at the low.

What is the month with the shortest days?

With an average of 8h and 54min of daylight, December has the shortest days of the year.

Average temperature
Rapid City, SD

Average temperature - Rapid City, SD

The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (32.5°F).

The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is February (17.8°F).

Average pressure
Rapid City, SD

Average pressure - Rapid City, SD

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed
Rapid City, SD

Average wind speed - Rapid City, SD

The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.2mph).

Average humidity
Rapid City, SD

Average humidity - Rapid City, SD

The month with the highest relative humidity is January (77%).
The months with the lowest relative humidity are August and September (50%).

Average rainfall
Rapid City, SD

Average rainfall - Rapid City, SD

The wettest month (with the highest rainfall) is May (2.28").
The driest month (with the least rainfall) is January (0.43").

Average rainfall days
Rapid City, SD

Average rainfall days - Rapid City, SD

The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is December (4.8 days).

Average snowfall
Rapid City, SD

Average snowfall - Rapid City, SD

The month with the highest snowfall is April (5.43").
The months with the least snowfall are June, July and August (0").

Average snowfall days
Rapid City, SD

Average snowfall days - Rapid City, SD

The month with the highest number of snowfall days is February (10.5 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight / Average sunshine
Rapid City, SD

Average daylight / Average sunshine - Rapid City, SD

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).

The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 54min).

Average sunshine days
Rapid City, SD

Average sunshine days - Rapid City, SD

The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (11 days).

Average UV index
Rapid City, SD

Average UV index - Rapid City, SD

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average visibility
Rapid City, SD

Average visibility - Rapid City, SD

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Rapid City, South Dakota, USA

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