Climateby Month

Sioux Falls, SD climate by month

NOAA 1991-2020 normals · 1,473 ft elevation

Summers in Sioux Falls are warm and often humid; winters are very cold and snowy. Highs peak at 85°F in July and fall to 27°F in January. Wet days are spread through the year, from about 6 to 12 a month. Normal snowfall is about 45 in a year. The most comfortable time to visit is May.

Warmest month
85°F
July normal high
Coldest month
9°F
January normal low
Wet days a year
104
27.9 in of precipitation
Snow a year
45.3 in
normal snowfall

How warm is Sioux Falls?

Normal highs range from 27°F in January to 85°F in July.

0°20°40°60°80°100° January: normal high 27°F (-3°C), low 9°F (-13°C) 27° 9° February: normal high 32°F (0°C), low 13°F (-11°C) March: normal high 45°F (7°C), low 24°F (-4°C) April: normal high 59°F (15°C), low 36°F (2°C) May: normal high 71°F (22°C), low 48°F (9°C) June: normal high 81°F (27°C), low 59°F (15°C) July: normal high 85°F (29°C), low 63°F (17°C) 85° 63° August: normal high 83°F (28°C), low 61°F (16°C) September: normal high 76°F (24°C), low 52°F (11°C) October: normal high 61°F (16°C), low 38°F (3°C) November: normal high 45°F (7°C), low 25°F (-4°C) December: normal high 32°F (0°C), low 13°F (-11°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Sioux Falls?

May has the most wet days (about 12); the year brings about 28 in of precipitation.

January: 7 wet days February: 7 wet days March: 8 wet days April: 10 wet days May: 12 wet days 12 June: 12 wet days July: 9 wet days August: 9 wet days September: 8 wet days October: 8 wet days November: 6 wet days 6 December: 7 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 45.3 in a year, most of it in December.

January: 8.0 in of snow February: 8.6 in of snow March: 7.2 in of snow April: 5.1 in of snow May: 0.1 in of snow June: 0.0 in of snow 0.0 July: 0.0 in of snow August: 0.0 in of snow September: 0.0 in of snow October: 1.4 in of snow November: 6.2 in of snow December: 8.7 in of snow 8.7 JFMAMJJASOND

How humid is Sioux Falls?

Muggy days peak in July, at about 12 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 4 muggy days July: 12 muggy days 12 August: 10 muggy days September: 2 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Joe Foss Field Airport, 3.3 mi NW of the city center.

How much daylight?

Daylight ranges from about 9.0 hours in December to 15.4 hours in June.

January: 9.4 hours of daylight February: 10.5 hours of daylight March: 11.9 hours of daylight April: 13.4 hours of daylight May: 14.7 hours of daylight June: 15.4 hours of daylight 15.4 July: 15.1 hours of daylight August: 13.9 hours of daylight September: 12.5 hours of daylight October: 11.0 hours of daylight November: 9.7 hours of daylight December: 9.0 hours of daylight 9.0 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Sioux Falls, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 27°F9°F 0.6 in7 8.0 in 0 9.4 h
February 32°F13°F 0.8 in7 8.6 in 0 10.5 h
March 45°F24°F 1.6 in8 7.2 in 0 11.9 h
April 59°F36°F 3.0 in10 5.1 in 0 13.4 h
May 71°F48°F 3.9 in12 0.1 in 0 14.7 h
June 81°F59°F 4.2 in12 0.0 in 4 15.4 h
July 85°F63°F 3.3 in9 0.0 in 12 15.1 h
August 83°F61°F 3.3 in9 0.0 in 10 13.9 h
September 76°F52°F 2.7 in8 0.0 in 2 12.5 h
October 61°F38°F 2.4 in8 1.4 in 0 11.0 h
November 45°F25°F 1.2 in6 6.2 in 0 9.7 h
December 32°F13°F 0.8 in7 8.7 in 0 9.0 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Sioux Falls

By our comfort score, the best month is May.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 270227
Feb 310321
Mar 453413
Apr 60963
May 731571
Jun 661173
Jul 58557
Aug 62854
Sep 681451
Oct 581042
Nov 392313
Dec 270225

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Sioux Falls

The last spring frost typically comes around May 1, and the first fall frost around Oct 6, leaving 157 frost-free days in a typical year.

Frost and freeze dates for Sioux Falls
Typical date1 year in 10
Last spring frost (32°F)May 1after May 14
First fall frost (32°F)Oct 6before Sep 23
Last hard freeze (28°F)Apr 22after May 5
First hard freeze (28°F)Oct 17before Oct 1
Frost-free season157 daysunder 138 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: Sioux Falls (USW00014944), NOAA 1991-2020 freeze probabilities. Frost dates for every city in South Dakota.

Hottest and coldest readings, 1991-2020

The highest reading was 107°F (July 12, 1995); the lowest was -30°F (January 2, 2010).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Similar climates elsewhere

Where the numbers come from

  • Temperature, rain, snowfall, snow depth, frost dates, humidity and wind by hour and cloud cover: Sioux Falls (USW00014944), 3.0 mi NNW of the city center, 1,430 ft . NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Joe Foss Field Airport (726510-14944), 3.3 mi NW of the city center, 1,419 ft (54 ft lower than the city). Hourly observations, 1991-2020.

Distances from the city center (USGS). Methodology · Report an error