December weather forecastRiverdale Park, MD
December
Weather in December
December, the first month of the winter in Riverdale Park, is also a frosty month, with an average temperature fluctuating between 45.5°F (7.5°C) and 34.3°F (1.3°C).Temperature
The advent of December brings a slight shift in average high-temperature, moving from a fresh 54.1°F (12.3°C) in November to a frosty 45.5°F (7.5°C). Nighttime temperatures in December average to an icy 34.3°F (1.3°C).Humidity
May, October and December, with an average relative humidity of 76%, are the most humid months.Rainfall
In December, the rain falls for 9.8 days. Throughout December, 2.6" (66mm) of precipitation is accumulated. In Riverdale Park, Maryland, during the entire year, the rain falls for 157.9 days and collects up to 31.14" (791mm) of precipitation.Snowfall
January through April and December are months with snowfall. December is the first month it typically snows. Throughout December, in the average 2.4 snowfall days, it receives 0.67" (17mm) of snow. In Riverdale Park, during the entire year, snow falls for 13.5 days and aggregates up to 7.2" (183mm) 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 the month, sunrise is at 7:08 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:26 am and sunset at 4:55 pm EST.
Sunshine
In Riverdale Park, the average sunshine in December is 5.1h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: In December, an average UV index of 2 transforms into the following instructions:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. A wide-brimmed hat provides unparalleled sun protection for sensitive areas like the eyes, ears, and neck. Warning! The reflection from snow can nearly magnify 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
Riverdale Park, MD
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.9°F).
- Average low temperature in December: 34.3°F
The month with the highest average low temperature is July (70°F).
The coldest month (with the lowest average low temperature) is January (27.7°F).
Average pressure in December
Riverdale Park, 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
Riverdale Park, MD
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in December
Riverdale Park, MD
- Average humidity in December: 76%
The months with the highest relative humidity are May, October and December (76%).
The months with the lowest relative humidity are April and July (71%).
Average rainfall in December
Riverdale Park, MD
- Average rainfall in December: 2.6"
The wettest month (with the highest rainfall) is August (3.58").
The driest month (with the least rainfall) is January (2.01").
Average rainfall days in December
Riverdale Park, MD
- Average rainfall days in December: 9.8 days
The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is November (9 days).
Average snowfall in December
Riverdale Park, MD
- Average snowfall in December: 0.67"
The month with the highest snowfall is January (2.6").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in December
Riverdale Park, MD
- Average snowfall days in December: 2.4 days
The month with the highest number of snowfall days is January (4.1 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
Riverdale Park, MD
- Average daylight in December: 9h and 30min
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 30min).
- Average sunshine in December: 5h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).
Average sunshine days in December
Riverdale Park, MD
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in December
Riverdale Park, 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 and December (UV index 2).
Average cloud cover in December
Riverdale Park, MD
- Average cloud cover in December: 45
The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).
Average visibility in December
Riverdale Park, 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).
