South Dakota has a temperate continental type of climate with warm and moderately humid summers and dry and cold winters. Nebraska to the south, Wyoming to the west, Montana to the northwest, North Dakota to the north, Minnesota to the east, and Iowa to the southeast share borders with the landlocked state. South Dakota, the Coyote state, is part of the American Midwest and lies in the Great Plains region, the land of many Indian reservations.
The Missouri River divides South Dakota into the distinct western and eastern parts called West River and East River. The Black Hills in the western part display a different climate subtype due to the unique geography - the mountains receive a high level of precipitation and have various species of pines such as the lodgepole and ponderosa. The majority of South Dakota is a temperate grassland prairie with hills, ravines, and flat-topped elevations occupying the rest - however, elms, willows, larches, and cottonwoods are common near the riverbeds. The western portion is semi-arid in places where the terrain is uneven and consists of badlands. The eastern part receives more rainfall than the western one and has few mountains of towering heights.
South Dakota summers range from warm to hot with the average high temperature of 80°F (26.7°C) to 90°F (32.2°C) in the peak of July whereas nights cool down quickly to register average temperatures of 50°F (10°C) to 60°F (15.6°C). Many days cross 100°F (37.8°C), particularly in the semi-arid western belts during severe hot and dry spells. Winters are severely cold in January when the average high temperatures are below freezing, while average low temperatures drop to 10°F (-12.2°C) in the majority of the state. Late spring and early summer bring moderate rainfall as South Dakota records average precipitation of 20" (508mm) during the year: the southeastern regions receive 25" (635mm), while the Black Hills see more than 30" (762mm) of annual rain. Snowfall in the mountain ranges is more than 100" (2540mm), while the plains regularly experience snow during the winter.
South Dakota is prone to thunderstorms and tornadoes, mainly in the southeastern part of the state that lies in the Tornado Alley of the country, during late spring and early summer. Winds blow at breakneck speeds across the great plains that are devoid of the high mountain ranges that lie westwards. Usta holds the record of the highest ever temperature of 120°F (48.9°C) on July 15, 2006, in South Dakota, while McIntosh recorded the coldest temperature of -54°F (-47.8°C) on February 17, 1936.
The best time to visit South Dakota
The best time to visit South Dakota is usually from late spring to autumn, particularly from May to October. Summer is typically the peak tourist season, but late spring and autumn are generally better regarding accommodation and fewer crowds. June to August tends to have hot, dry, and humid days with the mercury often close to 90°F (32.2°C). Late spring and early summer are prone to rain and thunderstorms, while autumn sees a reduction in storms and cooler temperatures than the summer. The fall season has pleasant weather with reduced humidity and rainfall. Summers swell with tourists eager to visit Mount Rushmore and the state and national parks.
The worst time to visit South Dakota
Winter is the worst time to visit South Dakota, with severe weather that often sees days and nights below freezing temperatures. The majority of the state sees a substantial amount of snow, and mountains have deep snow packs. Wind Cave national park receives 41" (1041.4mm) of snow, while Mount Rushmore records 52" (1320.8mm) - it is a better idea to visit these places during the warm seasons than the biting cold of winter. Local attractions draw some visitors to South Dakota during the winter, but the season registers significantly low tourist numbers compared to the summer.
South Dakota is vulnerable to wildfires, thunderstorms, and tornadoes in late spring and early summer. Wildfires are generally common in the dry and hot summer as the hills have many lodgepole and ponderosa forests, which are particularly susceptible to dry conditions. Southeastern parts of South Dakota see more thunderstorms and tornadoes - the state experiences around 30 tornadoes per year of various intensities that are mostly short of high-risk categories. Winters are prone to ice storms and blizzards.
Weather in January
January is by far the coldest month of the year in South Dakota, with the average low temperatures dropping to 2°F (-16.7°C) in the eastern regions - nights routinely go below the low temperatures in many places. Central and western South Dakota is in the frigid 6°F (-14.4°C) to 41°F (5°C) average range with short days and reduced daily sunshine. The western and central parts of the state are generally warmer than the eastern one. The historic Deadwood in the Black Hills averages between 14°F (-10°C) to 38°F (3.3°C), while Pierre, the capital of South Dakota, is in the cold range of 10°F (-12.2°C) to 30°F (-1.1°C) - comparatively Aberdeen on the eastern side is the coldest and lies in the range of 2°F (-16.7°C) to 23°F (-5°C). Snowfall is usually 5" (127mm) to 8" (203.2mm) in most parts of the state. Winds are strong and face little resistance from the topography of mainly temperate grasslands. South Dakota is not an ideal place to celebrate the New Year for most of the visitors, which reflects in the dwindling tourist numbers.
Weather in February
February is a chilly winter month in South Dakota as the landscape wrestles with the cold conditions. Nights are severely cold, and the entire state registers low freezing temperatures. The sunshine is usually weak and lasts for short periods in the dry and cold conditions. Sioux Falls, in the far southeast hardly sees the sunshine with the average temperatures in the 12°F (-11.1°C) to 31°F (-0.6°C) range, while Rapid City and Spearfish on the western part of the I-90 are between 18°F (-7.8°C) to 39°F (3.9°C) and 20°F (-6.7°C) to 41°F (5°C) respectively. Blizzards are common, deposit layers of snow and ice, and stall many towns and cities due to poor visibility and dangerous roads. Snowfall is 5" (127mm) to 7" (177.8mm) in the majority of the state. Most flora and fauna are asleep, and there are few reasons to visit South Dakota in February apart from ice fishing, ice-skating, and the likes - winter conditions close the mountain trails.
Weather in March
March is cold at the start of the spring season in South Dakota. It is a little damp with 1" (25.4mm) to 1.5" (38.1mm) of rain - the eastern part of the state receives more rain than the west. Average temperatures are between 20°F (-6.7°C) to 53°F (11.7°C) with western South Dakota warmer than the eastern portion. Watertown in the east has average temperatures in the cold 20°F (-6.7°C) to 39°F (3.9°C), while Hot Springs in the west is a little warm during the day and between 24°F (-4.4°C) to 53°F (11.7°C). Snowfall is persistent, and most of the areas register 5" (127mm) to 6" (152.4mm). Humidity is 60%, while there is an average of 14 sunny days in March. Early spring spots wildlife in many places like the Black Hills National Forest and Custer State Park. Bears, bison, coyotes, as well as birds, forage for food during the spring after the long winter cold, and it is an excellent idea to carry a repellent spray and stay away from them. Carry a raincoat or jacket, as the conditions are often wet and unpredictable!
Weather in April
April sees the advent of spring in entire South Dakota and mild day temperatures. Day temperatures are usually in the warm 50°F (10°C) to 60°F (15.6°C), while nights rise above freezing and are in the 32°F (0°C) to 35°F (1.7°C) across the state. Wind Cave National Park in western South Dakota averages between 31°F (-0.6°C) to 58°F (14.4°C) and sees a slight rise in tourist numbers. Rivers, lakes, and streams start to meltdown, and the sound and smell of freshwater are soothing in the backdrop of the mountains. Expect wet conditions and rain anytime - the rainfall in April is 2" (50.8mm) to 3" (76.2mm), while snowfall is in the range of 3" (76.2mm) to 4" (101.6mm) in the majority of the state. It is also the start of the hunting season in South Dakota - the eastern part has light geese, which serve the purpose, and it is a good idea to wear bright color clothes in the season to avoid a hunting accident. Wear layers of clothing when exploring the forests and parks or kayaking in the canyon waters.
Weather in May
May is beautiful, with many sunny days in South Dakota as the land blooms with tulips, and the birds sing songs of joy. Average high temperatures are in the warm 50°F (10°C) to 60°F (15.6°C) range, while the average low temperatures are in the comfortable 40°F (4.4°C) to 50°F (10°C). Snowfall tapers down by May, and most of the mountain trails are open for the tourist season. Tourist numbers swell in the temperate sun, and flora and fauna seem to erupt everywhere on the land. Spearfish Canyon sees waterfalls like the Roughlock Falls and Bridal Veil Falls roar with freshwater, and it is an excellent time for fishing, canoeing, and kayaking. May is wet, and rain accumulates up to 4" (101.6mm) in many places, so carry rain protection as hailstorms occur in fair numbers. Thunderstorms are fairly regular and can sometimes turn violent -, while May is a great time, keep an eye on the weather forecast for any extreme events.
Weather in June
June has pleasant summer temperatures in South Dakota that see tourists in droves visit its parks, wildlife, and American Indian historical monuments. Average high temperatures are in a temperate 60°F (15.6°C) to 70°F (21.1°C) range, while average low temperatures are comfortable between 50°F (10°C) to 60°F (15.6°C). June is rainy as most of the state register 4" (101.6mm) - it is moderately humid, and daylight lasts almost 15 hours with an average of 20 sunny days. Yankton in the east has average temperatures in the 57°F (13.9°C) to 82°F (27.8°C), while Mount Rushmore in the west is between 51°F (10.6°C) to 71°F (21.7°C) - no wonder it is full of enthusiastic visitors. South Dakota summers are vulnerable to thunderstorms and tornadoes - keep in mind that the southeastern part of the state lies in the Tornado Alley of the country. The weather is beautiful and suitable for swimming in the rivers and lakes. People enjoy sunbathing, particularly in the sunny days of early summer, when the sun rays have less intensity.
Weather in July
July is the hottest month of the year in South Dakota as the average temperatures in the state are in the range of 85°F (29.4°C) to 90°F (32.2°C). Several days and places cross the 100°F (37.8°C) mark as it becomes hot and humid. Sunny days average almost 24 in July, but it rains a fair amount of 3" (76.2mm) to 4" (101.6mm). Nights are delightful with average temperatures in the 55°F (12.8°C) to 65°F (18.3°C) range, which makes them ideal for camping and stargazing in the national and state parks. July is the peak of the tourist season that drives families during school vacations to South Dakota and camping grounds, mountain lodges and hotels are rarely vacant. The growing season, lush green pastures, pristine rivers and lakes, historical monuments of the Wild West along with brilliant sunshine swells up tourist numbers in South Dakota. Mountain trails are open, and activities such as hiking, biking, bird watching, hunting, among many others, gather momentum during the summer.
Weather in August
August is a beautiful summer month in South Dakota that sees moderately warm temperatures and brilliant sunshine. The average high temperatures are in the 75°F (23.9°C) to 85°F (29.4°C) range, while the average low temperatures are between 55°F (12.8°C) and 60°F (15.6°C). Rain is to the tune of 2" (50.8mm) to 3" (76.2mm) in the majority of the state. Although the rain is light, August experiences thunderstorms and is vulnerable to occasional tornadoes. Lemmon in western South Dakota averages between 57°F (13.9°C) to 85°F (29.4°C), Pickstown in the central portion 61°F (16.1°C) to 87°F (30.6°C), while the Waubay Wildlife Refuge in the east registers 60°F (15.6°C) to 81°F (27.2°C). The Black Hills in South Dakota consists of some of the tallest mountains east of the Rockies that receive moderate to heavy rainfall in August and are colder than the rest of the state. Light sweatshirts are sufficient in August to explore plains as well as the high mountain trails. Keep in mind that the grasslands have little shade as most of the trees are near the rivers, lakes, and the mountain slopes.
Weather in September
September begins the beautiful autumn season of South Dakota with its green prairie, forests, riversides, and mountains sprinkled in various shades of yellow, orange, red, and golden colors. The temperatures are moderate, and the average is between 45°F (7.2°C) to 75°F (23.9°C). Rain is to the tune of 2" (50.8mm) to 3" (76.2mm), and clouds cover the skies between many sunny days. Early fall is colder than the summer, especially during the midday, and high temperatures rarely rise above 90°F (32.2°C). All the mountain trails are open, the hunting and growing season are in full swing, and the weather is generally pleasant. An occasional thunderstorm makes its way through the southeast, but it is usually short-lived. The prairie is windy, as the vast plains have scattered mountain ranges and butte - steep flattop hills. September is a great time to visit the Badlands National Park - start in the early morning as the weather changes between sunshine and cloudy!
Weather in October
October is in the middle of the autumn season in South Dakota, with mild temperatures and unpredictable weather. The average high temperatures are between 55°F (12.8°C) to 62°F (16.7°C), while the average low temperatures are in 32°F (0°C) and 40°F (4.4°C) span. Rainfall is less in October as snowfall replaces the rain most of the time. Light snowflakes fall in most places as the state records an average of 1" (25.4mm) to 2" (50.8mm) of snow. Mountains easily register 10" (254mm) to 15" (381mm) of snow. Nights are usually cold and see light snow. Average low temperatures drop below freezing in many places such as Custer at 32°F (0°C), and Porcupine with 31°F (-0.6°C) in western South Dakota. October is an ideal time to watch sunrise and sunset at Sylvan Lake or spot bison and bighorn sheep around the Wildlife Loop. Brilliant fall colors make the landscape come alive - the green pines and orange aspens in the backdrop of granite hills and narrow roads are simply out of this world, and people are bound to stop their cars and forget time to enjoy the scenery!
Weather in November
November is the end of the beautiful autumn season in South Dakota that sees a sizeable drop in temperatures in the state. Average high temperatures are in the 40°F (4.4°C) to 50°F (10°C), while average low temperatures are below freezing and range in between 18°F (-7.8°C) to 27°F (-2.8°C). Brookings along the state highway 14 in eastern South Dakota is between 21°F (-6.1°C) to 40°F (4.4°C), Mobridge along state highway 12 in the central portion registers between 23°F (-5°C) to 41°F (5°C), while Custer along state highway 16 in the western portion is between 23°F (-5°C) to 44°F (6.7°C). November sees little rain but a moderate amount of snow to the tune of 5" (127mm) to 6" (152.4mm) in many parts of the state. Sunshine limits to 6 hours a day, and there are about 15 sunny days during the month. The ground quickly changes to white, and the conditions become windy and lean towards cold. November usually registers a few tourist numbers and ends the summer tourism in South Dakota, although there is no shortage of winter activities.
Weather in December
December is a cold winter month with moderate snowfall as average high temperatures are in the 25°F (-3.9°C) to 45°F (7.2°C) range and the average low temperatures are in the freezing 5°F (-15°C) to 19°F (-7.2°C) range across the state. The majority of the state sees 5" (127mm) to 10" (254mm) of snow, while Lead in the Black Hills accumulates 27" (685.8mm). December is mostly dry, with an average of 14 sunny days. December is the snowiest month, which mandates protection in the form of warm winter clothes as the strong gusts of wind make the temperatures feel colder than the actual mercury readings. Tourist numbers drop significantly, and those who remain behind are enthusiasts of skiing, snowmobiling, snowshoeing, and other winter activities. Winter sees only 5% of visitors of the summer to Mount Rushmore - the region is temperate than the rest of South Dakota, and the freeway from Keystone to the Memorial is regularly maintained to keep it free from snow as far as possible.