August weather forecast
Custer, SD

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Large, scenic rocks and trees around this tiny Sylvan Lake located in the tranquil Custer State Park in Custer City, South Dakota
Large, scenic rocks and trees around this tiny Sylvan Lake located in the tranquil Custer State Park in Custer City, South Dakota

Weather in August

As August arrives, Custer starts witnessing the measured fade of summer, unlike the peak summer seen in July. Declining temperatures and upcoming rainfall herald the close of the hot season. However, the differences are slight, keeping the atmosphere still comfortably warm. The arrival of August also indicates the end of the tourist peak season and the transition towards a relatively quieter time in the city. Despite being the tail-end of summer, outdoor enthusiasts can still enjoy Custer’s natural beauty with ease.

Temperature

The arrival of August in Custer brings an average high-temperature of a still warm 80.1°F (26.7°C), closely following the temperature pattern of July. Despite drastic daytime highs, Custer logs an average low-temperature reading of 58.3°F (14.6°C) throughout August.

Humidity

August and September, with an average relative humidity of 52%, are the least humid months.

Rainfall

In Custer, in August, it is raining for 16.6 days, with typically 2.56" (65mm) of accumulated precipitation. Throughout the year, in Custer, there are 135.4 rainfall days, and 20.39" (518mm) of precipitation is accumulated.

Snowfall

June through August are months without snowfall in Custer.

Daylight

The average length of the day in August in Custer, South Dakota, is 13h and 56min.
On the first day of the month, sunrise is at 5:44 am and sunset at 8:17 pm. On the last day of August, sunrise is at 6:17 am and sunset at 7:31 pm MDT.

Sunshine

August has the most sunshine of the year, with an average of 11.7h of sunshine.

UV index

In August, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.
Note: The maximum daily UV index of 5 during August translates into the following directions:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average August temperature in Custer?

The high-temperature, in August, in Custer, is 80.1°F (26.7°C), while the low-temperature averages to 58.3°F (14.6°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which represents the influence of relative humidity on air temperature, in July is appraised at 82.4°F (28°C).

What is the least humid month in Custer?

The months with the lowest humidity in Custer, South Dakota, are August and September, with an average relative humidity of 52%.

What is the average humidity in August in Custer?

In August, the average relative humidity in Custer, South Dakota, is 52%.

How much does it rain in Custer in August?

In Custer, in August, it is raining for 16.6 days, with typically 2.56" (65mm) of accumulated precipitation.

When it does not snow in Custer?

In Custer, South Dakota, snow does not fall in June through August.

Does it snow in Custer in August?

In Custer, in August, it doesn't snow. In September, it regularly snows.

What is the average length of the day in August in Custer?

The average day length in August in Custer, South Dakota, is 13h and 56min.

When is the sunrise / sunset in August in Custer?

In August, on the first day of the month, sunrise is at 5:44 am and sunset at 8:17 pm. On the last day of the month, in Custer, sunrise is at 6:17 am and sunset at 7:31 pm MDT.

What month has the most sunshine in Custer?

With an average of 11.7h of sunshine, August has the most sunshine of the year in Custer.

How many hours of sunshine does Custer have in August?

In August, the average sunshine duration in Custer, South Dakota, is 11.7h.

What is the UV index intensity in August in Custer?

In August, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium health risk from unsafe 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
Custer, SD

Average temperature in August - Custer, SD
  • Average high temperature in August: 80.1°F

The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is December (29.8°F).

  • Average low temperature in August: 58.3°F

The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is February (16.2°F).

Average pressure in August
Custer, SD

Average pressure in August - Custer, SD
  • Average pressure in August: 29.9"Hg

The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).

Average wind speed in August
Custer, SD

Average wind speed in August - Custer, SD
  • Average wind speed in August: 7mph

The windiest month (with the highest average wind speed) is April (9.5mph).
The calmest month (with the lowest average wind speed) is August (7mph).

Average humidity in August
Custer, SD

Average humidity in August - Custer, SD
  • Average humidity in August: 52%

The months with the highest relative humidity are January and February (77%).
The months with the lowest relative humidity are August and September (52%).

Average rainfall in August
Custer, SD

Average rainfall in August - Custer, SD
  • Average rainfall in August: 2.56"

The wettest month (with the highest rainfall) is June (3.19").
The driest month (with the least rainfall) is January (0.47").

Average rainfall days in August
Custer, SD

Average rainfall days in August - Custer, SD
  • Average rainfall days in August: 16.6 days

The month with the highest number of rainy days is May (18.6 days).
The month with the least rainy days is November (4.5 days).

Average snowfall in August
Custer, SD

Average snowfall in August - Custer, SD
  • Average snowfall in August: 0"

The month with the highest snowfall is April (7.24").
The months with the least snowfall are June, July and August (0").

Average snowfall days in August
Custer, SD

Average snowfall days in August - Custer, SD
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is February (12.9 days).
The months with the least snowfall days are June, July and August (0 days).

Average daylight in August /
Average sunshine in August
Custer, SD

Average daylight in August / Average sunshine in August - Custer, 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: 11h and 4min

The month with the most sunshine is August (Average sunshine: 11h and 42min).
The month with the least sunshine is February (Average sunshine: 6h and 0min).

Average sunshine days in August
Custer, SD

Average sunshine days in August - Custer, SD
  • Average sunshine days in August: 9.9 days

The month with the most sunshine days is November (19.2 days).
The month with the least sunshine days is May (7.8 days).

Average UV index in August
Custer, SD

Average UV index in August - Custer, SD
  • Average UV index in August: 5

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

Average cloud cover in August
Custer, SD

Average cloud cover in August - Custer, SD
  • Average cloud cover in August: 17

The month with the most cloud cover is April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 17).

Average visibility in August
Custer, SD

Average visibility in August - Custer, SD
  • Average visibility in August: 6mi

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

Custer, South Dakota, USA

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