December weather forecastUpper Marlboro, MD
December
Weather in December
The first month of the winter, December, is still a chilly month in Upper Marlboro, Maryland, with an average temperature varying between 45.7°F (7.6°C) and 34.7°F (1.5°C).Temperature
December's arrival signals a moderate reduction in the average high-temperature, easing from a fresh 54.5°F (12.5°C) in November to a chilly 45.7°F (7.6°C). In Upper Marlboro, December is marked by an average low-temperature of 34.7°F (1.5°C).Humidity
The average relative humidity in December is 76%.Rainfall
In Upper Marlboro, in December, during 11.1 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. In Upper Marlboro, during the entire year, the rain falls for 164.8 days and collects up to 32.87" (835mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Upper Marlboro, in December, snow falls for 2.5 days, with typically accumulated 1.06" (27mm) of snow. In Upper Marlboro, during the entire year, snow falls for 15.1 days and aggregates up to 8.5" (216mm) of snow.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:06 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:55 pm EST.
Sunshine
In December, the average sunshine is 5.2h.UV index
The months with the lowest UV index are January, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: An average UV index of 2 in December transforms into this advice:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Upper Marlboro, MD
- Average high temperature in December: 45.7°F
The warmest month (with the highest average high temperature) is July (86.7°F).
The month with the lowest average high temperature is January (40.1°F).
- Average low temperature in December: 34.7°F
The month with the highest average low temperature is July (69.8°F).
The coldest month (with the lowest average low temperature) is January (28.2°F).
Average pressure in December
Upper Marlboro, MD
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Upper Marlboro, MD
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest months (with the lowest average wind speed) are July and August (5.4mph).
Average humidity in December
Upper Marlboro, MD
- Average humidity in December: 76%
The month with the highest relative humidity is May (77%).
The months with the lowest relative humidity are January, March and April (72%).
Average rainfall in December
Upper Marlboro, MD
- Average rainfall in December: 2.68"
The wettest month (with the highest rainfall) is August (3.94").
The driest month (with the least rainfall) is January (2.05").
Average rainfall days in December
Upper Marlboro, MD
- Average rainfall days in December: 11.1 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is November (8.8 days).
Average snowfall in December
Upper Marlboro, MD
- Average snowfall in December: 1.06"
The month with the highest snowfall is January (2.76").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Upper Marlboro, MD
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is January (4.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Upper Marlboro, MD
- Average daylight in December: 9h and 30min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 5h and 12min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in December
Upper Marlboro, MD
- Average sunshine days in December: 16.7 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is July (10.8 days).
Average UV index in December
Upper Marlboro, MD
- 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, November and December (UV index 2).
Average cloud cover in December
Upper Marlboro, MD
- Average cloud cover in December: 44
The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in December
Upper Marlboro, MD
- 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).
