May 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 May

May in Custer is when signs of summer begin to appear, distinct from the somewhat chilly weather in April. A pleasant transformation is observed in the city’s climate, introducing residents and visitors to comfortably warm days. The temperatures increase, along with relative humidity levels, nurturing the growth of diverse flora across the city. However, residents can also expect a significant increase in rainfall, resulting from surplus evaporation. Despite the changes, May days still grant generous sunlight, boosting outdoor activities in the city.

Temperature

The start of May brings a rise in the average high-temperature, moving from a cool 50.9°F in April to an enjoyable 61°F. Custer's temperature drops to an average low of 42.4°F during the nights of May.

Humidity

In Custer, South Dakota, the average relative humidity in May is 66%.

Rainfall

In May, the rain falls for 18.6 days. Throughout May, 3.11" of precipitation is accumulated. In Custer, during the entire year, the rain falls for 135.4 days and collects up to 20.39" of precipitation.

Snowfall

Months with snowfall in Custer are January through May, September through December. May is the last month it regularly snows in Custer, South Dakota. During 3.4 snowfall days, in May, Custer aggregates 4.09" of snow. Throughout the year, there are 75.1 snowfall days, and 40.24" of snow is accumulated.

Daylight

In May, the average length of the day in Custer, South Dakota, is 14h and 45min.
On the first day of May, sunrise is at 5:46 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 5:15 am and sunset at 8:28 pm MDT.

Sunshine

In May, the average sunshine is 10.1h.

UV index

In May, the average daily maximum UV index in Custer is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: During May, 4 as the daily maximum UV index converts into the following advice:
Exercise prevention - Warding off sunburn is urged. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat. Be alert to the fact! The reflection from snow can nearly double the UV radiation of the Sun.
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FAQ

What are May temperatures in Custer?

May temperatures in Custer, South Dakota, vary between a high-temperature of 61°F and a low-temperature of 42.4°F.

What is the average humidity in May in Custer?

In May, the average relative humidity in Custer, South Dakota, is 66%.

How much does it rain in Custer in May?

In Custer, in May, during 18.6 rainfall days, 3.11" of precipitation is typically accumulated.

What is the last month it snows in Custer?

May is the last month it regularly snows in Custer. During 3.4 snowfall days, in May, Custer aggregates 4.09" of snow.

How many hours of daylight does Custer have in May?

In Custer, South Dakota, the average day length in May is 14h and 45min.

What time are sunrise and sunset in May in Custer?

In May, on the first day of the month, sunrise is at 5:46 am and sunset at 7:56 pm. On the last day of the month, in Custer, South Dakota, sunrise is at 5:15 am and sunset at 8:28 pm MDT.

How long on average sun shines in May in Custer?

In May, the average sunshine duration in Custer is 10.1h.

What is the UV index reading in May in Custer?

In Custer, the average daily maximum UV index in May is 4. A UV Index value of 3 to 5 symbolizes a medium health risk from exposure to Sun's UV rays.
Average high temperature
Average low temperature
Average pressure
Average wind speed
Average max. wind speed
Average wind speed gusts
Average humidity
Average rainfall
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 May
Custer, SD

Average temperature in May - Custer, SD
  • Average high temperature in May: 61°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 May: 42.4°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).

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Average pressure in May
Custer, SD

Average pressure in May - Custer, SD
  • Average pressure in May: 29.91"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).

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Average wind speed in May
Custer, SD

Average wind speed in May - Custer, SD
  • Average wind speed in May: 8.9mph

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).

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Average humidity in May
Custer, SD

Average humidity in May - Custer, SD
  • Average humidity in May: 66%

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

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Average rainfall in May
Custer, SD

Average rainfall in May - Custer, SD
  • Average rainfall in May: 3.11"

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

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Average rainfall days in May
Custer, SD

Average rainfall days in May - Custer, SD
  • Average rainfall days in May: 18.6 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).

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Average snowfall in May
Custer, SD

Average snowfall in May - Custer, SD
  • Average snowfall in May: 4.09"

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

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Average snowfall days in May
Custer, SD

Average snowfall days in May - Custer, SD
  • Average snowfall days in May: 3.4 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).

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

Average daylight in May / Average sunshine in May - Custer, SD
  • Average daylight in May: 14h 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 May: 10h and 1min

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).

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Average sunshine days in May
Custer, SD

Average sunshine days in May - Custer, SD
  • Average sunshine days in May: 7.8 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).

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Average UV index in May
Custer, SD

Average UV index in May - Custer, SD
  • Average UV index in May: 4

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).

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Average cloud cover in May
Custer, SD

Average cloud cover in May - Custer, SD
  • Average cloud cover in May: 35

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

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Average visibility in May
Custer, SD

Average visibility in May - Custer, SD
  • Average visibility in May: 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).

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Custer, South Dakota, USA

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