December weather forecastWilmington, DE
December
Weather in December
Completing the climatic cycle of the year, December in Wilmington is characterized by cold temperatures, decreased daylight hours and significantly increased snowfall. December is the first month since March to witness a conspicuous amount of snow, registering 1.54" (39mm). Transitioning from November, December sees a further drop in temperatures embracing the full brunt of winter. The calendar concludes with a clear forecast of what to expect in the ensuing month of January - low temperatures, heavy snowfall and high humidity.Temperature
Wilmington's weather in December involves a mild decrease in the average high-temperature, moving down slightly from November's cool 52.2°F (11.2°C) to a frosty 43.7°F (6.5°C). In Wilmington, the nighttime temperature averages to an icy 32.7°F (0.4°C) during December.Humidity
In December, the average relative humidity is 77%.Rainfall
In Wilmington, during December, the rain falls for 11.5 days and regularly aggregates up to 3.31" (84mm) of precipitation. Throughout the year, in Wilmington, there are 168.9 rainfall days, and 35.55" (903mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Wilmington, Delaware, in December, during 3.2 snowfall days, 1.54" (39mm) of snow is typically accumulated. Throughout the year, in Wilmington, Delaware, there are 21.9 snowfall days, and 12.05" (306mm) of snow is accumulated.Ocean temperature
In Wilmington, Delaware, in December, the average water temperature is 44.6°F (7°C).Note: Swimming in 44.6°F (7°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.
Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December in Wilmington, sunrise is at 7:04 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:47 pm EST.
Sunshine
In Wilmington, the average sunshine in December is 5h.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 reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for the average person.Note: In December, a regular UV index of 2 translates into these guidelines:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Stay sun-safe with clothing that is both closely woven and worn loosely. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Wilmington, DE
- Average high temperature in December: 43.7°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (37°F).
- Average low temperature in December: 32.7°F
The month with the highest average low temperature is July (68.4°F).
The coldest month (with the lowest average low temperature) is January (25.3°F).
Average pressure in December
Wilmington, DE
- Average pressure in December: 30.1"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
Wilmington, DE
- Average wind speed in December: 8mph
The windiest months (with the highest average wind speed) are January, February and March (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Wilmington, DE
- Average humidity in December: 77%
The month with the highest relative humidity is October (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in December
Wilmington, DE
- Average rainfall in December: 3.31"
The wettest month (with the highest rainfall) is August (4.09").
The driest month (with the least rainfall) is January (2.36").
Average rainfall days in December
Wilmington, DE
- Average rainfall days in December: 11.5 days
The month with the highest number of rainy days is May (18.7 days).
The month with the least rainy days is November (8.8 days).
Average snowfall in December
Wilmington, DE
- Average snowfall in December: 1.54"
The month with the highest snowfall is March (3.58").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Wilmington, DE
- Average snowfall days in December: 3.2 days
The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in December
Wilmington, DE
- Average sea temperature in December: 45°F
The best month for swimming (with the highest average sea temperature) is August (73°F).
The coldest month (with the lowest average sea temperature) is February (34°F).
Average daylight in December /
Average sunshine in December
Wilmington, DE
- 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 0min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in December
Wilmington, DE
- Average sunshine days in December: 15.9 days
The month with the most sunshine days is November (18.6 days).
The months with the least sunshine days are May and July (9.8 days).
Average UV index in December
Wilmington, DE
- 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
Wilmington, DE
- Average cloud cover in December: 46
The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in December
Wilmington, DE
- 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).
