December weather forecastWilliamsport, PA
December
Weather in December
December graces Williamsport with a taste of winter magic. The city captures the charm of the season with a meaningful increase in snowfall, an average depth of 1.38" (35mm) recorded. The temperature dips to a chilly 36.7°F (2.6°C) high, adding to the festive freezing spirit. The driest month in terms of rainfall, December shapes a perfect snow-globe setting. The diminishing daylight hours highlight the city lights and decorations, wrapping up another year weather.Temperature
December brings a decrease in the average high-temperature, shifting from a frosty 46.2°F (7.9°C) in November to an icy 36.7°F (2.6°C). December witnesses an average nighttime temperature of 26.6°F (-3°C).Humidity
In December, the average relative humidity is 83%.Rainfall
In Williamsport, during December, the rain falls for 10.6 days and regularly aggregates up to 1.14" (29mm) of precipitation. In Williamsport, during the entire year, the rain falls for 145.2 days and collects up to 16.57" (421mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Williamsport, during December, snow falls for 8.1 days and regularly aggregates up to 1.38" (35mm) of snow. Throughout the year, there are 39.1 snowfall days, and 7.56" (192mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:14 am and sunset at 4:39 pm. On the last day of the month, sunrise is at 7:33 am and sunset at 4:49 pm EST.
Sunshine
The average sunshine in December is 3.9h.UV index
The months with the lowest UV index are January through March, October through December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for the average person.Note: During December, 2 as the daily maximum UV index converts into the following advice:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. When the Sun is at its strongest around midday, find shade and limit exposure. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Beware! Reflection from snow can magnify the Sun's UV radiation nearly twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Williamsport, PA
- Average high temperature in December: 36.7°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in December: 26.6°F
The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Williamsport, PA
- Average pressure in December: 30.09"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 December
Williamsport, PA
- Average wind speed in December: 7mph
The windiest months (with the highest average wind speed) are January, March and April (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in December
Williamsport, PA
- Average humidity in December: 83%
The month with the highest relative humidity is February (84%).
The months with the lowest relative humidity are April and July (77%).
Average rainfall in December
Williamsport, PA
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is April (1.93").
The driest month (with the least rainfall) is November (0.94").
Average rainfall days in December
Williamsport, PA
- Average rainfall days in December: 10.6 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is February (7.5 days).
Average snowfall in December
Williamsport, PA
- Average snowfall in December: 1.38"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Williamsport, PA
- Average snowfall days in December: 8.1 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Williamsport, PA
- Average daylight in December: 9h and 18min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 3h and 54min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The months with the least sunshine are January and February (Average sunshine: 3h and 42min).
Average sunshine days in December
Williamsport, PA
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in December
Williamsport, PA
- Average UV index in December: 2
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 December
Williamsport, PA
- Average cloud cover in December: 59
The months with the most cloud cover are January and February (Cloud cover 60).
The month with the least cloud cover is July (Cloud cover 35).
Average visibility in December
Williamsport, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The month with the lowest visibility is September (4mi).
