Sioux Falls Weather in May
Sioux Falls in May sees pleasant daytime temperatures of 21°C (70°F) and nighttime lows of 8°C (46°F). Rainfall is fairly high this month at around 91 mm (3.6 in), so pack a rain jacket to stay dry.
Rainfall in Sioux Falls in May
Historically, May sees about 12 days of rain, with a monthly average of 91 mm (3.6 in). The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.
Temperature in Sioux Falls in May
May is a good time to be in Sioux Falls. Days are perfect, reaching 21°C (70°F), with nights around 8°C (46°F). Even when the weather is stable, mornings and evenings can still feel distinctly cool. Nights drop to 8°C (46°F). Cold nights like these are actually great for sleeping well, as long as you have a warm enough duvet.So this is a great month to visit if you prefer dry days with pleasant temperatures.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Sioux Falls's climate page.
Sioux Falls Temperature in May
Min Temperature
8°C (46°F)
Max Temperature
21°C (70°F)
Chance of Rain
41%
Precipitation
91 mm (3.6 in)
Rainy days
12 days
Humidity
64%
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Sioux Falls typically rise from around 19°C (66°F) at the start of May to approximately 24°C (75°F) by the end. Nights are cool, with lows typically ranging from 5°C (41°F) to 13°C (55°F).
Average temperatures in May
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in May
Historical weather for Sioux Falls in May
Browse day-by-day weather records for Sioux Falls spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Sioux Falls historical weather extremes in May
Based on weather observations in Sioux Falls between 1976 and 2026, these are the recorded extremes during May.
- On May 19, 2009, temperatures climbed to 35°C (95°F), marking the warmest May day on record.
- Sioux Falls registered its coldest May night on May 3, 2005, with temperatures dropping to -5°C (23°F).
Best Places in the United States of America in May
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in May →
perfect weather
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tolerable
unpleasant
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What to Wear in Sioux Falls in May
For Sioux Falls in May, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho.What To Do in Sioux Falls in May
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Sioux Falls's climate page.
See the full Sioux Falls climate overview or explore weather in the United States of America.
