April weather forecast
Keystone, SD

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Weather in April

The weather in Keystone further improves in April, providing a relief from the freezing winter months. The highest increase is seen in temperatures, with April featuring a high of 50.9°F (10.5°C), signaling the imminent arrival of summer. Shower clouds dominate the city's sky, making this the wettest month in Keystone. Longer daylight hours provide more opportunity for sightseeing. As the month of April gives way to May, the city witnesses the bloom of Spring in its full glory, with temperatures that are even more conducive to spending time outdoors.

Temperature

In Keystone, the onset of April comes with a modest high-temperature shift, transitioning from March's frosty 43.9°F (6.6°C) to a fresh 50.9°F (10.5°C). Keystone records a mean low-temperature of 32.5°F (0.3°C) in April.

Humidity

In April, the average relative humidity is 67%.

Rainfall

In Keystone, in April, during 13.3 rainfall days, 2.32" (59mm) of precipitation is typically accumulated. In Keystone, South Dakota, during the entire year, the rain falls for 135.4 days and collects up to 20.39" (518mm) of precipitation.

Snowfall

Months with snowfall are January through May, September through December. The month with the most snowfall in Keystone is April, when snow falls for 8.8 days and typically aggregates up to 7.24" (184mm) of snow.

Daylight

The average length of the day in April is 13h and 29min.
On the first day of the month, sunrise is at 6:33 am and sunset at 7:21 pm. On the last day of April, in Keystone, sunrise is at 5:45 am and sunset at 7:56 pm MDT.

Sunshine

In Keystone, the average sunshine in April is 9.5h.

UV index

In Keystone, the average daily maximum UV index in April is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: A maximum UV index of 3 in April translates into the following recommendations:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Be cautious! The UV radiation from the Sun can be magnified almost twofold by snow reflection.
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Frequently asked questions

What is the usual temperature for Keystone in April?

April temperatures in Keystone, South Dakota, vary between a high-temperature of 50.9°F (10.5°C) and a low-temperature of 32.5°F (0.3°C).

What is the average humidity in April in Keystone?

The average relative humidity in April in Keystone, South Dakota, is 67%.

How much does it rain in Keystone in April?

In April, in Keystone, South Dakota, the rain falls for 13.3 days. Throughout April, 2.32" (59mm) of precipitation is accumulated.

What is the snowiest month in Keystone?

April is the month with the most snowfall in Keystone, South Dakota. Snow falls for 8.8 days and accumulates 7.24" (184mm) of snow.

How much does it snow in Keystone in April?

In Keystone, South Dakota, in April, during 8.8 snowfall days, 7.24" (184mm) of snow is typically accumulated.

How many hours of daylight does Keystone have in April?

The average day length in April in Keystone is 13h and 29min.

When are sunrise and sunset in April in Keystone?

In April, on the first day of the month, sunrise is at 6:33 am and sunset at 7:21 pm. On the last day of the month, in Keystone, sunrise is at 5:45 am and sunset at 7:56 pm MDT.

How long on average sun shines in April in Keystone?

In April, the average sunshine duration in Keystone, South Dakota, is 9.5h.

What is the UV index intensity in April in Keystone?

In Keystone, the average daily maximum UV index in April is 3. A UV Index estimate of 3 to 5 represents a medium health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in April
Keystone, SD

Average temperature in April - Keystone, SD
  • Average high temperature in April: 50.9°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 April: 32.5°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 April
Keystone, SD

Average pressure in April - Keystone, SD
  • Average pressure in April: 29.92"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 April
Keystone, SD

Average wind speed in April - Keystone, SD
  • Average wind speed in April: 9.5mph

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 April
Keystone, SD

Average humidity in April - Keystone, SD
  • Average humidity in April: 67%

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 April
Keystone, SD

Average rainfall in April - Keystone, SD
  • Average rainfall in April: 2.32"

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 April
Keystone, SD

Average rainfall days in April - Keystone, SD
  • Average rainfall days in April: 13.3 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 April
Keystone, SD

Average snowfall in April - Keystone, SD
  • Average snowfall in April: 7.24"

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 April
Keystone, SD

Average snowfall days in April - Keystone, SD
  • Average snowfall days in April: 8.8 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 April /
Average sunshine in April
Keystone, SD

Average daylight in April / Average sunshine in April - Keystone, SD
  • Average daylight in April: 13h and 3min

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 April: 9h and 3min

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 April
Keystone, SD

Average sunshine days in April - Keystone, SD
  • Average sunshine days in April: 9.8 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 April
Keystone, SD

Average UV index in April - Keystone, SD
  • Average UV index in April: 3

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 April
Keystone, SD

Average cloud cover in April - Keystone, SD
  • Average cloud cover in April: 38

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 April
Keystone, SD

Average visibility in April - Keystone, SD
  • Average visibility in April: 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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Keystone, South Dakota, USA

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