May weather forecastWilliamstown, PA
May
Weather in May
The last month of the spring, May, is a pleasant month in Williamstown, Pennsylvania, with temperature in the range of an average low of 50.4°F (10.2°C) and an average high of 69.3°F (20.7°C).Temperature
May's arrival is marked by an increase in the average high-temperature, moving from a mild 58.6°F (14.8°C) in April to an agreeable 69.3°F (20.7°C). During the nights in May, Williamstown experiences a consistent average temperature of 50.4°F (10.2°C).Humidity
The average relative humidity in May is 81%.Rainfall
May is the month with the most rainfall. Rain falls for 17.4 days and accumulates 2.95" (75mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. May is the last month it regularly snows. During 0.3 snowfall days, in May, Williamstown aggregates 0.2" (5mm) of snow. Throughout the year, there are 26.2 snowfall days, and 12.32" (313mm) of snow is accumulated.Daylight
The average length of the day in May is 14h and 28min.On the first day of the month, sunrise is at 6:04 am and sunset at 8:02 pm. On the last day of May, sunrise is at 5:37 am and sunset at 8:30 pm EDT.
Sunshine
In May, the average sunshine is 8.2h.UV index
The average daily maximum UV index in May is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: In May, the maximum UV index of 5 transforms into these recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Williamstown, PA
- Average high temperature in May: 69.3°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in May: 50.4°F
The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure in May
Williamstown, PA
- Average pressure in May: 30.01"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in May
Williamstown, PA
- Average wind speed in May: 6.3mph
The windiest months (with the highest average wind speed) are March and April (8.3mph).
The calmest month (with the lowest average wind speed) is August (4.6mph).
Average humidity in May
Williamstown, PA
- Average humidity in May: 81%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (76%).
Average rainfall in May
Williamstown, PA
- Average rainfall in May: 2.95"
The wettest month (with the highest rainfall) is May (2.95").
The driest month (with the least rainfall) is February (1.54").
Average rainfall days in May
Williamstown, PA
- Average rainfall days in May: 17.4 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (7.2 days).
Average snowfall in May
Williamstown, PA
- Average snowfall in May: 0.2"
The month with the highest snowfall is March (3.43").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Williamstown, PA
- Average snowfall days in May: 0.3 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Williamstown, PA
- Average daylight in May: 14h and 30min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in May: 8h and 12min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in May
Williamstown, PA
- Average sunshine days in May: 10.8 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is May (10.8 days).
Average UV index in May
Williamstown, PA
- 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, March, November and December (UV index 2).
Average cloud cover in May
Williamstown, PA
- Average cloud cover in May: 49
The months with the most cloud cover are February and December (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in May
Williamstown, PA
- Average visibility in May: 5mi
The months with the highest visibility are January, March, April, June, July, November and December (6mi).
The months with the lowest visibility are February, May, August, September and October (5mi).
