December weather forecastPort Jefferson, OH
December
Weather in December
December, the first month of the winter in Port Jefferson, is also an icy month, with temperature in the range of an average low of 27.5°F (-2.5°C) and an average high of 37.8°F (3.2°C).Temperature
Port Jefferson's progression into December includes a drop in the average high-temperature, from a chilly 48.4°F (9.1°C) in November to a wintry 37.8°F (3.2°C). Port Jefferson, during the month of December, experiences an average low-temperature of 27.5°F (-2.5°C).Humidity
January, February and December, with an average relative humidity of 83%, are the most humid months.Rainfall
In Port Jefferson, during December, the rain falls for 7 days and regularly aggregates up to 0.55" (14mm) of precipitation. Throughout the year, there are 111.7 rainfall days, and 8.58" (218mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Port Jefferson, in December, snow falls for 6.1 days, with typically accumulated 0.47" (12mm) of snow. In Port Jefferson, during the entire year, snow falls for 27.1 days and aggregates up to 2.8" (71mm) of snow.Daylight
December has the shortest days of the year in Port Jefferson, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:40 am and sunset at 5:10 pm. On the last day of the month, sunrise is at 7:59 am and sunset at 5:20 pm EST.
Sunshine
The average sunshine in December in Port Jefferson is 3.9h.UV index
The months with the lowest UV index in Port Jefferson, Ohio, are January, February, October through December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for the average person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Port Jefferson, OH
- Average high temperature in December: 37.8°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (32°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in December
Port Jefferson, OH
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Port Jefferson, OH
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is January (10.6mph).
The calmest month (with the lowest average wind speed) is August (5.8mph).
Average humidity in December
Port Jefferson, OH
- Average humidity in December: 83%
The months with the highest relative humidity are January, February and December (83%).
The month with the lowest relative humidity is October (75%).
Average rainfall in December
Port Jefferson, OH
- Average rainfall in December: 0.55"
The wettest months (with the highest rainfall) are May and June (1.06").
The driest month (with the least rainfall) is November (0.47").
Average rainfall days in December
Port Jefferson, OH
- Average rainfall days in December: 7 days
The month with the highest number of rainy days is May (13.2 days).
The month with the least rainy days is February (5 days).
Average snowfall in December
Port Jefferson, OH
- Average snowfall in December: 0.47"
The month with the highest snowfall is February (0.79").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Port Jefferson, OH
- Average snowfall days in December: 6.1 days
The month with the highest number of snowfall days is January (7.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Port Jefferson, OH
- Average daylight in December: 9h and 24min
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 24min).
- Average sunshine in December: 3h and 54min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in December
Port Jefferson, OH
- Average sunshine days in December: 21 days
The month with the most sunshine days is November (21.8 days).
The month with the least sunshine days is July (13.6 days).
Average UV index in December
Port Jefferson, OH
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in December
Port Jefferson, OH
- Average cloud cover in December: 60
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in December
Port Jefferson, OH
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, October, November and December (6mi).
The months with the lowest visibility are August and September (5mi).
