Memorial Day in South Dakota usually brings a mix of spring warmth and a decent chance for rain. Most years, daytime highs land in the mid-70s, while nighttime lows drop to the low 50s, and there’s about a 50% shot at some precipitation. You could have a lovely afternoon but still want a jacket handy for cool evenings or unexpected showers.
Weather patterns shift depending on where you are in the state. Eastern cities like Sioux Falls feel more humid, while western spots near Rapid City are drier and a bit cooler.
Planning outdoor events gets tricky, but knowing the averages helps set your expectations.
If you dig through decades of weather records, you’ll see Memorial Day has brought everything from record highs over 100 degrees to mornings near freezing. That’s a pretty wide range, so keeping both sunscreen and a raincoat nearby just makes sense.
Typical Memorial Day Weather in South Dakota
Memorial Day in South Dakota usually brings mild to warm temperatures and a moderate chance of rain. The sky can be sunny or cloudy, and conditions change based on whether you’re in the eastern plains, central regions, or western Black Hills.
Average Temperatures on Memorial Day
Late May temperatures in South Dakota tend to be comfortable. In Sioux Falls, for example, the long-term average high sits around 75°F (24°C), with lows near 52°F (11°C).
Central and western areas like Pierre and Rapid City might run a few degrees warmer or cooler, depending on elevation and local weather.
Highs sometimes climb into the 80s or even low 90s. In 1934, Sioux Falls hit a record 104°F (40°C) on Memorial Day.
On the flip side, lows can dip into the 30s, with the coldest at 30°F (-1°C) back in 1897.
This range means you’ll want to plan for springlike mornings and summerlike afternoons. Light jackets work in the morning, but by midday, short sleeves usually feel best.
Precipitation Patterns
Rain on Memorial Day happens, but it’s usually light. In Sioux Falls, the long-term average is about 0.12 inches of precipitation, though half of past years have seen at least some rain.
Most showers are quick, tied to passing spring systems.
Heavy rain doesn’t happen often, but it’s not unheard of. Sioux Falls picked up nearly 2 inches on May 30, 1943.
Thunderstorms can pop up, especially in the eastern half of the state, where warm, humid air from the Midwest meets cooler northern air.
Snow is extremely rare on Memorial Day, but a late-season cold front could bring flakes to the higher elevations of the Black Hills. For most folks, expect rain, not snow.
Sunshine and Cloud Cover
Expect a mix of sunshine and clouds across South Dakota on Memorial Day. Many years, the sky is partly sunny, with clouds building in the afternoon when showers or storms might show up.
Clear skies are more common in the west, especially around Rapid City and the Black Hills, where drier air rules. Eastern South Dakota sees more cloud cover thanks to moisture drifting in from neighboring states.
Daylight stretches long this time of year. The sun rises early and sets after 8:30 p.m., so you get plenty of time for outdoor activities, whether that’s visiting parks, attending ceremonies, or just driving around.
Regional Weather Variations Across South Dakota
Weather in South Dakota changes a lot depending on your location. Elevation, geography, and distance from the Missouri River all affect how warm or wet your Memorial Day weekend feels.
Eastern South Dakota Conditions
In the east, including cities like Sioux Falls and Aberdeen, you’ll usually see warmer and more humid weather around Memorial Day. Average highs reach the low to mid-70s °F, with lows in the 50s °F.
Rain is common, and about half of Memorial Days record measurable precipitation.
Storm chances go up here because of higher humidity. Thunderstorms can develop in the afternoon or evening and sometimes bring brief heavy rain or hail.
Wind speeds stay moderate but can jump quickly during storms.
If you’re planning to be outside, expect things to feel more like summer than spring. Pack for both warm sunshine and possible wet weather.
Western South Dakota Climate
Western South Dakota, including Rapid City and the Black Hills, tends to be drier and cooler. Average highs run in the upper 60s to low 70s °F, while overnight lows often dip into the 40s °F.
The higher elevation in the Black Hills keeps nights crisp, even when the day warms up.
Rain falls less often than in the east, but afternoon showers still happen. Snow is rare by late May, though a few flakes have surprised people in the hills during odd years.
Winds blow stronger here, especially in the open plains west of the Missouri River.
Prepare for bigger temperature swings between day and night. A light jacket comes in handy for mornings and evenings, even if afternoons feel mild.
Central South Dakota Weather Differences
Central South Dakota, including Pierre, sits between the eastern and western patterns. Daytime highs usually hit the low to mid-70s °F, with lows in the upper 40s to low 50s °F.
Rain chances are moderate, but storms don’t show up as often as in the east.
Humidity stays lower than in Sioux Falls but higher than Rapid City. Winds can be steady, especially near the Missouri River valley.
The open landscape lets storms move through quickly, sometimes passing in less than an hour.
If you’re in central South Dakota for Memorial Day, expect comfortable afternoons and maybe a short rain shower. Bring layers, since temperatures can shift fast between sun and shade.
Historical Weather Trends for Memorial Day
Memorial Day weather in South Dakota shows a lot of variety in temperature and rainfall. You could get chilly mornings, hot afternoons, or storms that shake things up.
Record Highs and Lows
South Dakota’s Memorial Day temperatures have swung wildly over the decades. In Sioux Falls, record highs have hit the low to mid-90s °F. Record lows have dropped into the 30s °F.
Years like 1934, 1944, and 1953 saw highs in the 90s, while 1947 had a morning low near 37–38°F.
These numbers show how fast things can change, even during the same holiday weekend.
Average highs in late May usually sit in the 70s °F, but swings of 20 degrees or more aren’t unusual. Packing both light clothes and a jacket is just smart if you’re heading outside.
Notable Weather Events
Strong winds and storms have hit on several Memorial Days in South Dakota. Some years, gusts of 30–50 mph have swept across the east, especially near Sioux Falls and along the Iowa-Minnesota border.
Rain shows up pretty often, too. About one-third to one-half of Memorial Days in the region have measurable precipitation, sometimes from quick showers and sometimes from longer-lasting systems.
Severe weather occasionally lines up with the holiday. Thunderstorms with hail and lightning aren’t rare and can disrupt outdoor gatherings or travel. Stay aware of changing conditions if you’ll be outside.
Long-Term Climate Patterns
Long-term climate records show Memorial Day in South Dakota often marks the shift from spring to summer. The average high temperature trends toward the low to mid-70s °F, but past records prove both cool and hot days are possible.
Precipitation data points to late May as a relatively wet period. Moisture from the Gulf of Mexico often fuels storm systems that reach the northern Plains.
About half of the holidays have stayed dry, while the rest have included rain or storms. Predicting the weather for outdoor plans is tough without a reliable forecast close to the date.
Weather Forecasting for Memorial Day
When you plan for Memorial Day in South Dakota, you need more than just averages. Daily forecasts give you the details on temperature, rain, and storm chances that can affect outdoor events, travel, and safety.
How to Find the Latest Forecasts
You’ll get the most reliable Memorial Day forecasts from trusted sources like the National Weather Service (NWS), local TV stations, and regional radio updates. These outlets provide daily updates with temperature highs and lows, wind speeds, and precipitation chances.
Smartphone apps from the NWS or private services like AccuWeather and Weather.com offer radar maps and alerts. These come in handy if you’re traveling between cities like Sioux Falls, Rapid City, or Aberdeen, since conditions can change.
For quick checks, bookmark the NWS South Dakota page or set up mobile alerts. That way, you’ll get warnings about severe thunderstorms, flooding, or high winds, which are common in late May.
Having more than one source helps you double-check details and avoid relying on just one forecast.
Interpreting Local Forecasts
Forecasts often mention chance of precipitation or partly cloudy. In South Dakota, a 40% chance of rain means at least 40% of the forecast area could see measurable rain, not that it’ll rain 40% of the day.
Temperature ranges matter, too. For Memorial Day, highs usually reach the low to mid-70s °F in the east and can be a bit warmer in the west. Nighttime lows often fall into the 40s or 50s, which can feel chilly after a warm afternoon.
Keep an eye on wind speeds. Winds above 20 mph are common on the plains and can make things feel cooler or mess with outdoor grilling and camping.
If severe weather is possible, forecasts will mention thunderstorm timing, hail size, and tornado risk.
Forecast Accuracy and Limitations
Short-term forecasts, just a day or two ahead, are the most accurate. You can usually trust temperature predictions within a few degrees and rainfall chances with fair confidence.
But South Dakota sits in the northern Plains and is prone to sudden changes. Storm systems can shift quickly, especially in late spring when warm and cold air masses collide.
A dry forecast one day can turn stormy the next.
Long-range outlooks, like those 7–10 days before Memorial Day, show trends, not exact predictions. Use them to plan clothes and travel flexibility, but always check updated forecasts as the holiday gets closer. That way, you can adjust to changing conditions and avoid surprises.
Planning Outdoor Activities Around the Weather
Late May in South Dakota often brings mild to warm days, cool evenings, and a higher chance of rain or storms. You can still enjoy plenty of outdoor activities if you plan around the daily weather and prepare for sudden changes.
Best Times of Day for Events
Morning and late afternoon usually offer the most comfortable weather for outdoor plans. Temperatures often start in the 50s °F and rise into the 70s or low 80s °F by midday.
Midday can feel warm, especially in the east, so it’s smart to schedule hikes, picnics, or ceremonies earlier or later to avoid peak heat.
Evenings cool down quickly, often dropping into the 50s °F. Late-day events feel pleasant, but you’ll want a light jacket or sweater.
If you’re hosting a gathering, pick shaded spots or open spaces with airflow. In western South Dakota, afternoon winds can pick up, so securing tents or equipment is a good idea.
Tips for Staying Comfortable
Pack clothing you can layer. A short-sleeve shirt works well during the day, but you’ll probably want a light jacket after sunset.
Comfortable walking shoes help, since grass or trails might be damp after rain.
Bring sun protection. Even with some clouds, UV levels run high in late May. A wide-brim hat, sunglasses, and sunscreen help prevent sunburn.
Stay hydrated. Warm afternoons and outdoor activity can dehydrate you faster than you think. Keep water handy, especially if you’ll be outside for a while.
If you’re heading to a festival or community event, check if seating is on grass or pavement. Bringing a blanket or portable chair can make things a lot more comfortable.
Weather-Related Safety Precautions
Thunderstorms pop up a lot in South Dakota around Memorial Day. They can bring heavy rain, hail, and some pretty strong winds.
Always check the forecast before heading out. It’s smart to have a backup indoor plan too, just in case.
If you hear thunder, head inside or get into a vehicle right away. Lightning sometimes strikes miles away from the actual storm.
Stay away from open fields, tall trees, or anything metal.
Heavy downpours can trigger flash flooding, especially near rivers or in low spots. Don’t drive through flooded roads, even if the water doesn’t look deep.
Strong winds might show up as well. Tie down canopies, grills, and any other outdoor gear so nothing blows away or causes trouble.
Comparing Memorial Day Weather to Other Times of Year
Temperatures in South Dakota around Memorial Day usually show that spring’s winding down and summer’s starting up. Rain chances are still higher than what you get in mid-summer, but the warmer weather feels more reliable than it did earlier in spring.
A lot of folks use the holiday weekend as a marker when planning outdoor stuff.
Spring Versus Summer Weather
Spring in South Dakota is honestly a bit of a rollercoaster. One day might be in the 50s, and then suddenly you’ll get a day in the 80s.
Rainfall comes around more often in April and May, and thunderstorms start to pop up as spring moves along.
By Memorial Day, average highs usually hit the low to mid-70s °F. Lows hang out in the 40s or 50s.
That’s warmer and steadier than April, but you’re still looking at cooler and wetter weather than July.
Summer, especially July and August, really cranks up the heat and dries things out. Highs often land in the 80s or 90s, and nights stay in the 60s.
Severe storms can still happen, but you’ll usually see less rain than in late spring.
Key difference: Memorial Day weather feels like the start of summer, but you still get spring’s unpredictable side. You might enjoy some great afternoons, but sudden showers or chilly mornings can sneak up on you.
Memorial Day Compared to Other Holidays
When you look at Memorial Day next to other U.S. holidays, the differences really pop out. Independence Day in July? That one’s usually much hotter, with sticky humidity and not much rain to cool things off.
Highs often shoot past 90°F, so it definitely feels like the peak of summer heat in South Dakota.
Labor Day rolls around in early September, and it’s cooler than July, but still warmer than late May. Most days hit the upper 70s or low 80s, and nights feel milder compared to Memorial Day.
Rain chances drop off a bit compared to what you get in spring.
Earlier spring holidays, like Easter, bring a whole different vibe. The weather just can’t make up its mind then.
You might still see snow in March or early April, and sometimes it’s a full 20 to 30 degrees colder than late May.
Comparison table:
| Holiday | Typical Highs (°F) | Typical Lows (°F) | Rain/Snow Risk |
|---|---|---|---|
| Easter (Mar/Apr) | 40s–60s | 20s–40s | Snow or rain |
| Memorial Day (late May) | 70s–mid 70s | 40s–50s | Rain, storms |
| Independence Day (July) | 80s–90s | 60s | Lower rain |
| Labor Day (Sept) | 70s–80s | 50s–60s | Occasional rain |
So, Memorial Day really lands right at that seasonal turning point. It’s warmer than spring, but you don’t get the full-on midsummer heat yet.