Sioux Falls climate

Name: Sioux Falls
Address: US

Sioux Falls is warmest in July, with average highs of 28 °C, and coldest in January, when nights average -12 °C. June is the wettest month (133 mm) and January the driest (21 mm). Figures are 1991–2020 climate normals.

Across a full year Sioux Falls averages 798 mm of rain, 87 days above 25 °C and 141 days below freezing.

United States · 448 m elevation · population 171,544 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month July 28 °C
Coldest month January -12 °C
Driest month January 21 mm
Wettest month June 133 mm
Least cloud September 42 % cloud
Hottest on record August 38 °C
Coldest on record February -38 °C

What to expectSioux Falls through the year

Sioux Falls has a clear annual cycle: average daily highs run from -3.1 °C in January to 28 °C in July, a swing of 31 °C in mean temperature across the year.

Counted across a normal year, 87 days a year reach 25 °C, 21 of them reach 30 °C, 141 nights drop below freezing. The warmest reading in the 1991–2020 record is 38 °C, in August.

Rain is strongly seasonal. June averages 133 mm against 21 mm in January — 6.5 times as much. Planning around the dry months matters more here than planning around temperature.

Month by month

Month	Avg high	Rainfall	Cloud
January	-3.1 °C	21 mm	62 %
February	0.2 °C	24 mm	60 %
March	7.4 °C	48 mm	60 %
April	14.5 °C	90 mm	60 %
May	20.6 °C	111 mm	59 %
June	25.7 °C	133 mm	53 %
July	28.2 °C	81 mm	42 %
August	27.1 °C	84 mm	44 %
September	23.3 °C	77 mm	42 %
October	15.4 °C	61 mm	49 %
November	6.4 °C	40 mm	55 %
December	-0.9 °C	27 mm	61 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C	Days below 0 °C
January	-3.1 °C	-12.1 °C	-8.3 °C	12.3 °C	-34.6 °C	0	0	30
February	0.2 °C	-9.7 °C	-5.7 °C	18.6 °C	-37.8 °C	0	0	27
March	7.4 °C	-3.7 °C	0.9 °C	25.8 °C	-29.0 °C	0	0	22
April	14.5 °C	2.9 °C	8.0 °C	30.0 °C	-15.0 °C	1	0	9
May	20.6 °C	9.7 °C	14.7 °C	33.3 °C	-3.7 °C	7	1	0
June	25.7 °C	15.6 °C	20.4 °C	35.4 °C	5.5 °C	18	3	0
July	28.2 °C	18.3 °C	23.0 °C	37.3 °C	9.5 °C	25	9	0
August	27.1 °C	17.3 °C	21.8 °C	38.0 °C	7.0 °C	22	6	0
September	23.3 °C	13.1 °C	17.6 °C	33.9 °C	-0.9 °C	12	2	0
October	15.4 °C	5.7 °C	9.8 °C	29.3 °C	-10.8 °C	2	0	4
November	6.4 °C	-2.2 °C	1.4 °C	24.5 °C	-26.6 °C	0	0	19
December	-0.9 °C	-8.9 °C	-5.4 °C	16.5 °C	-31.9 °C	0	0	29

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	21 mm	5	9.3 h/day	62 %	75 %	23 km/h
February	24 mm	5	10 h/day	60 %	71 %	24 km/h
March	48 mm	7	12 h/day	60 %	69 %	24 km/h
April	90 mm	10	13 h/day	60 %	65 %	25 km/h
May	111 mm	12	15 h/day	59 %	66 %	24 km/h
June	133 mm	12	15 h/day	53 %	70 %	23 km/h
July	81 mm	8	15 h/day	42 %	71 %	20 km/h
August	84 mm	9	14 h/day	44 %	72 %	20 km/h
September	77 mm	8	13 h/day	42 %	67 %	23 km/h
October	61 mm	7	11 h/day	49 %	66 %	24 km/h
November	40 mm	6	9.7 h/day	55 %	70 %	23 km/h
December	27 mm	5	9.0 h/day	61 %	75 %	23 km/h

How Sioux Falls compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Sioux Falls	28 °C	-12 °C	798 mm	87
Omaha · United States	30 °C	-8.7 °C	893 mm	112
Lincoln · United States	31 °C	-7.6 °C	811 mm	120
Minneapolis · United States	28 °C	-13 °C	828 mm	81

Where Sioux Falls ranks

Ranking	Position	Value
The coolest places in North America in December	14th of 50	-0.9 °C
The coolest places in North America in January	14th of 50	-3.1 °C
The coolest places in North America in November	15th of 50	6.4 °C
The coolest places in North America in February	25th of 50	0.2 °C
The coolest places in North America year-round	31st of 50	14 °C
Places with the best weather in North America in September	35th of 50	90/100

Planning a trip? See the best time to visit Sioux Falls.

QuestionsCommon questions about Sioux Falls’s climate

When is the best time to visit Sioux Falls?

That depends on what you want, so the honest answer is a comparison rather than a single month. June, August, September sit closest to 20 °C on average, July is the warmest month and January the driest. The month-by-month table above has the full picture.

How hot does Sioux Falls get?

In July, the warmest month, daily highs average 28 °C. About 21 days a year pass 30 °C. The highest value in the 1991–2020 record is 38 °C.

How cold does it get in winter?

Nights average -12 °C in January, the coldest month. A normal year has 141 nights below freezing.

Which month is wettest in Sioux Falls?

June, averaging 133 mm over 12 days with rain. The driest month is January with 21 mm. The year as a whole averages 798 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Sioux Falls rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Data point: 43.544°, -96.728° , 448 m above sea level (the coordinates the reanalysis values are taken for)
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.