December weather forecastMarcus Hook, PA
December
Weather in December
December, the first month of the winter in Marcus Hook, is also a frosty month, with an average temperature varying between 32.9°F (0.5°C) and 44.1°F (6.7°C).Temperature
Marcus Hook observes a small decrease in the average high-temperature with the arrival of December, falling from November's cool 52.7°F (11.5°C) to a frosty 44.1°F (6.7°C). Marcus Hook experiences an average temperature drop to an icy 32.9°F (0.5°C) during December nights.Humidity
February, October and December, with an average relative humidity of 77%, are the most humid months.Rainfall
In Marcus Hook, in December, during 8.7 rainfall days, 2.32" (59mm) of precipitation is typically accumulated. In Marcus Hook, during the entire year, the rain falls for 148.4 days and collects up to 25.94" (659mm) of precipitation.Snowfall
January through May, November and December are months with snowfall. In Marcus Hook, in December, during 1.5 snowfall days, 0.91" (23mm) of snow is typically accumulated. In Marcus Hook, during the entire year, snow falls for 12.6 days and aggregates up to 7.28" (185mm) of snow.Ocean temperature
In Marcus Hook, the average seawater temperature in December is 47.8°F (8.8°C).Note: If planning to swim in 47.8°F (8.8°C) under 50°F (10°C), wear a protective suit. Neglecting this advice might cause immediate cold shock and troubled breathing. A splash around 55.4°F (13°C) is not much warmer.
Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:04 am and sunset at 4:37 pm. On the last day of December, sunrise is at 7:22 am and sunset at 4:47 pm EST.
Sunshine
In Marcus Hook, Pennsylvania, the average sunshine in December is 5.1h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for ordinary individuals.Note: The UV index of 2 during December translates into the following guidance:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Always opt for UVA and UVB-resistant sunglasses on radiant days. 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 December
Marcus Hook, PA
- Average high temperature in December: 44.1°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 (37.4°F).
- Average low temperature in December: 32.9°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in December
Marcus Hook, PA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Marcus Hook, PA
- Average wind speed in December: 7.9mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in December
Marcus Hook, PA
- Average humidity in December: 77%
The months with the highest relative humidity are February, October and December (77%).
The month with the lowest relative humidity is April (71%).
Average rainfall in December
Marcus Hook, PA
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is August (3.11").
The driest month (with the least rainfall) is January (1.61").
Average rainfall days in December
Marcus Hook, PA
- Average rainfall days in December: 8.7 days
The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (7.1 days).
Average snowfall in December
Marcus Hook, PA
- Average snowfall in December: 0.91"
The month with the highest snowfall is March (2.32").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Marcus Hook, PA
- Average snowfall days in December: 1.5 days
The month with the highest number of snowfall days is February (3.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average sea temperature in December
Marcus Hook, PA
- Average sea temperature in December: 47.7°F
The best month for swimming (with the highest average sea temperature) is August (75.9°F).
The coldest month (with the lowest average sea temperature) is February (39.9°F).
Average daylight in December /
Average sunshine in December
Marcus Hook, PA
- Average daylight in December: 9h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 5h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in December
Marcus Hook, PA
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is July (11.3 days).
Average UV index in December
Marcus Hook, PA
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Marcus Hook, PA
- Average cloud cover in December: 45
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in December
Marcus Hook, PA
- Average visibility in December: 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).





