May weather forecastRapid City, SD
May
Weather in May
May manifests classic spring weather features in Rapid City. Residents begin to appreciate the warmer temperatures, extended daylight hours, and the beautiful blossoming flora associated with spring. Average rainfall during this time is 2.28" (58mm), with daylight spanning for an impressive 14.8 hours. The propensity for clear skies increases, increasing sunshine exposure for the city. Wind speed decreases slightly, marking an exceptionally calmer atmosphere.Temperature
As May sets, the average high-temperature shows an increase, moving up from a cool 53.2°F (11.8°C) in April to a comfortable 63.1°F (17.3°C). An average nighttime temperature of 45.3°F (7.4°C) is witnessed throughout May.Humidity
In May, the average relative humidity is 64%.Rainfall
The month with the most rainfall is May, when the rain falls for 17.1 days and typically aggregates up to 2.28" (58mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. May is the last month it regularly snows. During 1.3 snowfall days, in May, Rapid City aggregates 1.46" (37mm) of snow. In Rapid City, during the entire year, snow falls for 50.4 days and aggregates up to 24.41" (620mm) of snow.Daylight
The average length of the day in May is 14h and 47min.On the first day of May, sunrise is at 5:42 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 5:12 am and sunset at 8:28 pm MDT.
Sunshine
In Rapid City, the average sunshine in May is 10.1h.UV index
The average daily maximum UV index in May is 5. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In May, a regular UV index of 5 translates into these guidelines:
Ensure safety - Sun damage prevention is strongly urged. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Rapid City, SD
- Average high temperature in May: 63.1°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is December (32.5°F).
- Average low temperature in May: 45.3°F
The month with the highest average low temperature is July (63.3°F).
The coldest month (with the lowest average low temperature) is February (17.8°F).
Average pressure in May
Rapid City, SD
- Average pressure in May: 29.91"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.84"Hg).
Average wind speed in May
Rapid City, SD
- Average wind speed in May: 9.8mph
The windiest month (with the highest average wind speed) is April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.2mph).
Average humidity in May
Rapid City, SD
- Average humidity in May: 64%
The month with the highest relative humidity is January (77%).
The months with the lowest relative humidity are August and September (50%).
Average rainfall in May
Rapid City, SD
- Average rainfall in May: 2.28"
The wettest month (with the highest rainfall) is May (2.28").
The driest month (with the least rainfall) is January (0.43").
Average rainfall days in May
Rapid City, SD
- Average rainfall days in May: 17.1 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is December (4.8 days).
Average snowfall in May
Rapid City, SD
- Average snowfall in May: 1.46"
The month with the highest snowfall is April (5.43").
The months with the least snowfall are June, July and August (0").
Average snowfall days in May
Rapid City, SD
- Average snowfall days in May: 1.3 days
The month with the highest number of snowfall days is February (10.5 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in May /
Average sunshine in May
Rapid City, SD
- Average daylight in May: 14h and 48min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in May: 10h and 6min
The month with the most sunshine is August (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 54min).
Average sunshine days in May
Rapid City, SD
- Average sunshine days in May: 11 days
The month with the most sunshine days is November (20.2 days).
The month with the least sunshine days is May (11 days).
Average UV index in May
Rapid City, SD
- Average UV index in May: 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 May
Rapid City, SD
- Average cloud cover in May: 34
The months with the most cloud cover are February and April (Cloud cover 38).
The month with the least cloud cover is August (Cloud cover 16).
Average visibility in May
Rapid City, 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).
