Sioux Falls, SD Weather
Sioux Falls hourly forecast: next 24 hours
Today's high of 72°F (22°C) is about 4°F (2°C) below the typical September high of 76°F (24°C).
Current conditions in detail
Sioux Falls weather tomorrow (Wednesday, September 16)
Tomorrow in Sioux Falls looks overcast, with a high of 69° and an overnight low of 56°. Precipitation chance is modest at 36%. Winds top out near 15 mph, and the UV index reaches 5 (moderate).
Sioux Falls 14-day forecast
About the weather in Sioux Falls
The Sioux Falls year is defined by how long its winter lasts: 5 months average sub-freezing nights, bottoming out in January at 11°F (-11°C). Summer is the short exception, with July reaching 83°F (28°C).
Sioux Falls weather: quick facts
- Hottest month: July - highs near 83°F (28°C)
- Coldest month: January - highs near 27°F (-3°C)
- Decade extremes (2015-2024): 102°F (39°C) high · -24°F (-31°C) low
- Wettest month: May (12 rainy days) · Sunniest: July (13.2 h sun/day)
- Climate type: humid continental
- Annual swing: 31°C between the average warmest and coolest month · day to night: 10°C
- Snow: about 19 days a year
- Months with freezing average lows: 5
- Average humidity: 68%
Temperatures through the year
January is the coolest month, with highs of 27°F (-3°C) and lows near 11°F (-11°C). Warmth peaks in July: highs of 83°F (28°C), lows of 65°F (18°C). The gridded 2015-2024 daily record for this location tops out at 102°F (39°C) and bottoms at -24°F (-31°C) - decade extremes, not all-time station records. July is the brightest month at 13.2 hours of sun a day, against an annual average of 9.2.
Rain, sun and snow
Overnight lows average at or below freezing for 5 months, November through March. Precipitation concentrates in May - 4.3 inches (110 mm) on 12 days - and thins out by February. Between the average July and the average January lie 31°C, a wider spread than 97% of the 3496 cities in our dataset.
Season by season
Spring (March through May)
Spring in Sioux Falls stays on the cool side of mild, with daytime highs averaging 57°F (14°C) and nights around 37°F (3°C); expect showers on roughly 28 days across the season, plus about 5 snowy days.
Summer (June through August)
Through summer, Sioux Falls sits firmly in the heat: 82°F (28°C) by day, 63°F (17°C) after dark, and expect showers on roughly 26 days across the season. Daylight is generous - around 12.5 hours of sun a day.
Fall (September through November)
Fall stays on the cool side of mild here - highs near 60°F (16°C), nights near 43°F (6°C), and expect showers on roughly 20 days across the season, plus about 2 snowy days.
Winter (December through February)
Through winter, Sioux Falls brings deep cold: 30°F (-1°C) by day, 14°F (-10°C) after dark, and rain comes on about 16 days over the three months, plus about 11 snowy days. Wind sharpens cold like this considerably; pair the forecast winds with the wind speed converter to judge exposed conditions.
Average temperatures in Sioux Falls by month
| Month | High | Low | Rain days | Precipitation | Sunshine | Humidity |
|---|---|---|---|---|---|---|
| January | 27° | 11° | 5 | 1.0 in | 6.1 h/day | 75% |
| February | 31° | 13° | 5 | 0.9 in | 7.9 h/day | 66% |
| March | 45° | 26° | 6 | 2.2 in | 8.3 h/day | 66% |
| April | 56° | 36° | 10 | 3.6 in | 9.2 h/day | 62% |
| May | 69° | 49° | 12 | 4.3 in | 10.3 h/day | 65% |
| June | 81° | 62° | 10 | 4.0 in | 12.8 h/day | 64% |
| July | 83° | 65° | 7 | 2.6 in | 13.2 h/day | 70% |
| August | 81° | 63° | 9 | 3.2 in | 11.4 h/day | 72% |
| September | 76° | 58° | 8 | 2.7 in | 10.1 h/day | 67% |
| October | 59° | 42° | 7 | 2.5 in | 8.0 h/day | 64% |
| November | 45° | 29° | 5 | 1.5 in | 6.9 h/day | 68% |
| December | 33° | 18° | 6 | 1.5 in | 5.9 h/day | 73% |