September weather forecast and climate
Sioux Falls, SD

The Sioux Falls in South Dakota, flowing downstream over rocks under the perfect evening skyline
The Sioux Falls in South Dakota, flowing downstream over rocks under the perfect evening skyline

Weather in September

September, the first month of the autumn, in Sioux Falls, is still a warm month, with temperature in the range of an average high of 74.3°F (23.5°C) and an average low of 53.2°F (11.8°C).

Temperature

In Sioux Falls, the average high-temperature slightly decreases, from a moderately hot 81.1°F (27.3°C) in August, to a still warm 74.3°F (23.5°C). In Sioux Falls, the average low-temperature is 53.2°F (11.8°C).

Humidity

The average relative humidity in September is 70%.

Rainfall

In Sioux Falls, during September, the rain falls for 10.5 days and regularly aggregates up to 1.89" (48mm) of precipitation. Throughout the year, there are 117.1 rainfall days, and 20.71" (526mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

The average length of the day in September is 12.5h.

Sunshine

In September, the average sunshine is 8.8h.

UV index

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from the exposure to the Sun's UV radiation for ordinary individuals.
Note: The daily maximum UV index of 4 interpret into the following advice:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
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FAQ

What is the temperature in September in Sioux Falls?

In Sioux Falls, South Dakota, in September, the average high-temperature is 74.3°F (23.5°C), and the average low-temperature is 53.2°F (11.8°C).

What is the average humidity in September in Sioux Falls?

In Sioux Falls, South Dakota, the average relative humidity in September is 70%.

How much does it rain in Sioux Falls in September?

In Sioux Falls, in September, during 10.5 rainfall days, 1.89" (48mm) of precipitation is typically accumulated.

Does it snow in Sioux Falls in September?

In Sioux Falls, in September, it doesn't snow. In October, it regularly snows.

When it does not snow in Sioux Falls?

June through September are months without snowfall.

How many hours of daylight does Sioux Falls have in September?

In September, the average length of the day is 12.5h.

How many hours of sunshine does Sioux Falls have in September?

In September, the average sunshine is 8.8h.

What is the UV index reading in September in Sioux Falls?

In Sioux Falls, South Dakota, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health threat from unprotected exposure to the UV radiation.

Average temperature in September
Sioux Falls, SD

Average temperature in September - Sioux Falls, SD
  • Average high temperature in September: 74.3°F

The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (23.4°F).

  • Average low temperature in September: 53.2°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (9.7°F).

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Average pressure in September
Sioux Falls, SD

Average pressure in September - Sioux Falls, SD
  • Average pressure in September: 29.98"

The month with the highest atmospheric pressure is January (30.16").
The month with the lowest atmospheric pressure is June (29.86").

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Average wind speed in September
Sioux Falls, SD

Average wind speed in September - Sioux Falls, SD
  • Average wind speed in September: 9.4mph

The windiest month (with the highest average wind speed) is April (11.3mph).
The calmest month (with the lowest average wind speed) is July (8mph).

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Average humidity in September
Sioux Falls, SD

Average humidity in September - Sioux Falls, SD
  • Average humidity in September: 70%

The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is October (66%).

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Average rainfall in September
Sioux Falls, SD

Average rainfall in September - Sioux Falls, SD
  • Average rainfall in September: 1.89"

The wettest month (with the highest rainfall) is June (3.27").
The driest months (with the least rainfall) are January, February and November (0.67").

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Average rainfall days in September
Sioux Falls, SD

Average rainfall days in September - Sioux Falls, SD
  • Average rainfall days in September: 10.5 days

The month with the highest number of rainy days is June (17.8 days).
The month with the least rainy days is February (3 days).

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Average snowfall in September
Sioux Falls, SD

Average snowfall in September - Sioux Falls, SD
  • Average snowfall in September: 0"

The month with the highest snowfall is February (4.25").
Months with the least snowfall are June, July, August and September (0").

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Average snowfall days in September
Sioux Falls, SD

Average snowfall days in September - Sioux Falls, SD
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (11.8 days).
Months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Sioux Falls, SD

Average daylight in September / Average sunshine in September - Sioux Falls, SD
  • Average daylight in September: 12.5h

The month with the longest days is June (Average daylight: 15.4h).
The month with the shortest days is December (Average daylight: 9h).

  • Average sunshine in September: 8.8h

The month with the most sunshine is July (Average sunshine: 10.7h).
The month with the least sunshine is January (Average sunshine: 4h).

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Average sunshine days in September
Sioux Falls, SD

Average sunshine days in September - Sioux Falls, SD
  • Average sunshine days in September: 17.7 days

The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is June (10 days).

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Average UV index in September
Sioux Falls, SD

Average UV index in September - Sioux Falls, SD
  • Average UV index in September: 4

Months with the highest UV index are June and July (UV index 6).
Months with the lowest UV index are January, February, November and December (UV index 2).

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Average cloud cover in September
Sioux Falls, SD

Average cloud cover in September - Sioux Falls, SD
  • Average cloud cover in September: 29

The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is July (Cloud cover 27).

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Average visibility in September
Sioux Falls, SD

Average visibility in September - Sioux Falls, SD
  • Average visibility in September: 6mi

Months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).

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