Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
The transition to May introduces an increase in the average high-temperature, shifting from a refreshing 63.7°F (17.6°C) in April to an agreeable 72.9°F (22.7°C). During May, Keystone observes a consistent average nighttime temperature of 52.2°F (11.2°C).Humidity
In Keystone, the average relative humidity in May is 78%.Rainfall
May is the month with the most rainfall. Rain falls for 19.7 days and accumulates 3.19" (81mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. May is the last month it regularly snows. During 0.3 snowfall days, in May, Keystone aggregates 0.39" (10mm) of snow. Throughout the year, there are 38.6 snowfall days, and 20" (508mm) of snow is accumulated.Daylight
The average length of the day in May is 14h and 12min.On the first day of May, sunrise is at 6:29 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 6:06 am and sunset at 8:40 pm EDT.
Sunshine
In May, the average sunshine is 9.1h.UV index
The average daily maximum UV index in May is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 5 during May translates into the following guidance:
Adopt protective measures - It is advised to guard against sun damage. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in May?
What is the average humidity in May?
What is the rainiest month in Keystone?
How much does it rain in May?
What is the last month it snows?
What is the average length of the day in May?
When is the sunrise / sunset in May in Keystone?
How many hours of sunshine does Keystone have in May?
What is the UV index intensity in May?
Average temperature in May
Keystone, WV
- Average high temperature in May: 72.9°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (39.2°F).
- Average low temperature in May: 52.2°F
The month with the highest average low temperature is July (60.3°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in May
Keystone, WV
- Average pressure in May: 30.03"Hg
The month with the highest atmospheric pressure is November (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.99"Hg).
Average wind speed in May
Keystone, WV
- Average wind speed in May: 5.9mph
The windiest month (with the highest average wind speed) is January (7.3mph).
The calmest month (with the lowest average wind speed) is August (4.2mph).
Average humidity in May
Keystone, WV
- Average humidity in May: 78%
The month with the highest relative humidity is February (82%).
The months with the lowest relative humidity are July, August and November (76%).
Average rainfall in May
Keystone, WV
- Average rainfall in May: 3.19"
The wettest month (with the highest rainfall) is May (3.19").
The driest month (with the least rainfall) is September (1.54").
Average rainfall days in May
Keystone, WV
- Average rainfall days in May: 19.7 days
The month with the highest number of rainy days is May (19.7 days).
The months with the least rainy days are January and November (10.1 days).
Average snowfall in May
Keystone, WV
- Average snowfall in May: 0.39"
The month with the highest snowfall is December (4.41").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Keystone, WV
- Average snowfall days in May: 0.3 days
The month with the highest number of snowfall days is January (10.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Keystone, WV
- Average daylight in May: 14h and 1min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in May: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in May
Keystone, WV
- Average sunshine days in May: 9.2 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is May (9.2 days).
Average UV index in May
Keystone, WV
- Average UV index in May: 5
The months with the highest UV index are June and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in May
Keystone, WV
- Average cloud cover in May: 43
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are June and August (Cloud cover 36).
Average visibility in May
Keystone, WV
- Average visibility in May: 5mi
The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).
Keystone, West Virginia, USA
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