Contents
- Weather in April
- Frequently asked questions
- Average temperature in April
- Average pressure in April
- Average wind speed in April
- Average humidity in April
- Average rainfall in April
- Average rainfall days in April
- Average snowfall in April
- Average snowfall days in April
- Average daylight in April
- Average sunshine in April
- Average sunshine days in April
- Average UV index in April
- Average cloud cover in April
- Average visibility in April
Weather in April
Temperature
The start of April brings a subtle shift in the average high-temperature, edging up from March's chilly 43.9°F (6.6°C) to a cool 50.9°F (10.5°C). In the month of April, Keystone witnesses a consistent average low-temperature of 32.5°F (0.3°C).Humidity
In Keystone, the average relative humidity in April is 67%.Rainfall
In Keystone, during April, the rain falls for 13.3 days and regularly aggregates up to 2.32" (59mm) of precipitation. In Keystone, 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. April is the month with the most snowfall. Snow falls for 8.8 days and accumulates 7.24" (184mm) of snow.Daylight
The average length of the day in April is 13h and 29min.On the first day of April, sunrise is at 6:33 am and sunset at 7:21 pm. On the last day of the month, sunrise is at 5:45 am and sunset at 7:56 pm MDT.
Sunshine
The average sunshine in April is 9.5h.UV index
The average daily maximum UV index in April is 3. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: A daily maximum UV index of 3 in April translates into the following instructions:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Boost your sun resistance with garments that are densely woven yet spacious. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are April temperatures?
What is the average humidity in April?
How much does it rain in April?
When does it snow the most?
How many days does it snow in April?
What is the average length of the day in April?
When are sunrise and sunset in April?
How long on average sun shines in April?
What is the UV index reading in April?
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).
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).
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).
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%).
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").
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).
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").
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).
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).
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).
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).
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).
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).
Keystone, South Dakota, USA
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