August weather forecast
Sioux Falls, SD

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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 August

August in Sioux Falls offers a slight reprieve from the peak summer warmth prevalent in July. However, with the temperature dropping slightly to 81.1°F (27.3°C), the weather remains pleasantly warm. The mild decrease in rainfall to 2.24" (57mm) signifies the gradual easing into the autumnal cycle. Despite the heat, daily sunshine hours marginally decrease, hinting at incoming fall. Sioux Falls in August straddles the threshold between the intense summer and the forthcoming pleasant fall season.

Temperature

The arrival of August brings an average high-temperature of a still moderately hot 81.1°F (27.3°C), closely following the temperature pattern of July. Contrary to the day's heat, an average low-temperature of 59.5°F (15.3°C) is recorded during the nights in August.

Heat index

Throughout August, the heat index is evaluated at a hot 86°F (30°C). Staying active during long-term exposure might result in a state of exhaustion and cause heat cramps.
When referencing the heat index, its values are suitable for shady environments and light breezes. Under direct sunshine, the heat index values might be elevated by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a measure that combines air temperature and relative humidity into a single value that indicates how hot the weather feels. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Awareness of direct sun exposure is crucial as it has the potential to heighten the weather's effects, pushing up the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.

Humidity

The average relative humidity in August is 73%.

Rainfall

In Sioux Falls, in August, it is raining for 13.2 days, with typically 2.24" (57mm) of accumulated precipitation. In Sioux Falls, during the entire year, the rain falls for 117.1 days and collects up to 20.71" (526mm) of precipitation.

Snowfall

June through September are months without snowfall.

Daylight

In Sioux Falls, South Dakota, the average length of the day in August is 13h and 55min.
On the first day of August, sunrise is at 6:17 am and sunset at 8:49 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 8:03 pm CDT.

Sunshine

In Sioux Falls, the average sunshine in August is 9.9h.

UV index

In Sioux Falls, the average daily maximum UV index in August is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum UV index of 5 during August translates into these guidelines:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Updated: Aug 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Sioux Falls in August?

In August, in Sioux Falls, the average high-temperature is 81.1°F (27.3°C), and the average low-temperature is 59.5°F (15.3°C). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines relative humidity and air temperature, is evaluated at 86°F (30°C).

What is the average humidity in August in Sioux Falls?

In Sioux Falls, the average relative humidity in August is 73%.

How much does it rain in August?

In Sioux Falls, during August, the rain falls for 13.2 days and regularly aggregates up to 2.24" (57mm) of precipitation.

When it does not snow?

In Sioux Falls, snow does not fall in June through September.

What is the average length of the day in August?

In Sioux Falls, the average day length in August is 13h and 55min.

When are sunrise and sunset in August?

On the first day of August in Sioux Falls, sunrise is at 6:17 am and sunset at 8:49 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 8:03 pm CDT.

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

In Sioux Falls, the average sunshine duration in August is 9.9h.

What is the UV index intensity in August?

In Sioux Falls, the average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a medium hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Sioux Falls, SD

Average temperature in August - Sioux Falls, SD
  • Average high temperature in August: 81.1°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 August: 59.5°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).

Average pressure in August
Sioux Falls, SD

Average pressure in August - Sioux Falls, SD
  • Average pressure in August: 29.93"Hg

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

Average wind speed in August
Sioux Falls, SD

Average wind speed in August - Sioux Falls, SD
  • Average wind speed in August: 8.1mph

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).

Average humidity in August
Sioux Falls, SD

Average humidity in August - Sioux Falls, SD
  • Average humidity in August: 73%

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

Average rainfall in August
Sioux Falls, SD

Average rainfall in August - Sioux Falls, SD
  • Average rainfall in August: 2.24"

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").

Average rainfall days in August
Sioux Falls, SD

Average rainfall days in August - Sioux Falls, SD
  • Average rainfall days in August: 13.2 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).

Average snowfall in August
Sioux Falls, SD

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

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

Average snowfall days in August
Sioux Falls, SD

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

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

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

Average daylight in August / Average sunshine in August - Sioux Falls, SD
  • Average daylight in August: 13h and 5min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in August: 9h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).

Average sunshine days in August
Sioux Falls, SD

Average sunshine days in August - Sioux Falls, SD
  • Average sunshine days in August: 15.1 days

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

Average UV index in August
Sioux Falls, SD

Average UV index in August - Sioux Falls, SD
  • Average UV index in August: 5

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

Average cloud cover in August
Sioux Falls, SD

Average cloud cover in August - Sioux Falls, SD
  • Average cloud cover in August: 30

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

Average visibility in August
Sioux Falls, SD

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

The 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).

Sioux Falls, South Dakota, USA

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