May weather forecastMount Vernon, SD
May
Weather in May
The last month of the spring, May, is a pleasant month in Mount Vernon, South Dakota, with an average temperature ranging between max 68.4°F (20.2°C) and min 50°F (10°C).Temperature
May's arrival signals a temperature shift, moving from a moderate 56.8°F (13.8°C) in April to a pleasant 68.4°F (20.2°C). During May, Mount Vernon sees a mean low-temperature of 50°F (10°C).Humidity
The average relative humidity in May is 69%.Rainfall
May is the month with the most rainfall. Rain falls for 13.5 days and accumulates 1.65" (42mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in May is 14h and 45min.On the first day of the month, sunrise is at 6:23 am and sunset at 8:36 pm. On the last day of May, sunrise is at 5:54 am and sunset at 9:07 pm CDT.
Sunshine
In May, the average sunshine is 9h.UV index
In May, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.Note: During May, 5 as the daily maximum UV index converts into the following advice:
Undertake protective steps - Recommendations to avoid sunburn are issued. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Sunglasses that ward off UVA and UVB rays play a pivotal role in reducing solar eye damage. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Mount Vernon, SD
- Average high temperature in May: 68.4°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (24.4°F).
- Average low temperature in May: 50°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (10.2°F).
Average pressure in May
Mount Vernon, SD
- Average pressure in May: 29.92"Hg
The months with the highest atmospheric pressure are January and February (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in May
Mount Vernon, SD
- Average wind speed in May: 9.8mph
The windiest month (with the highest average wind speed) is April (11.2mph).
The calmest month (with the lowest average wind speed) is July (8.6mph).
Average humidity in May
Mount Vernon, SD
- Average humidity in May: 69%
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are September and October (63%).
Average rainfall in May
Mount Vernon, SD
- Average rainfall in May: 1.65"
The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are February and November (0.28").
Average rainfall days in May
Mount Vernon, SD
- Average rainfall days in May: 13.5 days
The month with the highest number of rainy days is June (13.6 days).
The month with the least rainy days is February (1.9 days).
Average snowfall in May
Mount Vernon, SD
- Average snowfall in May: 0"
The month with the highest snowfall is February (1.42").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Mount Vernon, SD
- Average snowfall days in May: 0.1 days
The month with the highest number of snowfall days is January (8.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Mount Vernon, SD
- Average daylight in May: 14h and 42min
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: 9h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in May
Mount Vernon, SD
- Average sunshine days in May: 14 days
The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is June (12.8 days).
Average UV index in May
Mount Vernon, SD
- Average UV index in May: 5
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in May
Mount Vernon, SD
- Average cloud cover in May: 38
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 22).
Average visibility in May
Mount Vernon, 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).





