Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December is marked by a subtle drop in average high-temperatures, transitioning from a cool 53.6°F (12°C) in November to a frosty 45.3°F (7.4°C). The average nighttime temperature lowers to a wintry 33.3°F (0.7°C) throughout December.Humidity
May, October and December, with an average relative humidity of 75%, are the most humid months.Rainfall
In Adelphi, in December, during 10.4 rainfall days, 2.44" (62mm) of precipitation is typically accumulated. In Adelphi, during the entire year, the rain falls for 154.8 days and collects up to 30.28" (769mm) of precipitation.Snowfall
January through April, November and December are months with snowfall. In Adelphi, in December, snow falls for 2.5 days, with typically accumulated 1.34" (34mm) of snow. Throughout the year, there are 15 snowfall days, and 9.17" (233mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.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, in Adelphi, sunrise is at 7:26 am and sunset at 4:55 pm EST.
Sunshine
In December, the average sunshine is 5h.UV index
January, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for average individuals.Note: In December, an average UV index of 2 transforms into the following instructions:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average December temperature?
What is the most humid month in Adelphi?
What is the average humidity in December?
How many days does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Adelphi have in December?
When is the sunrise / sunset in December in Adelphi?
How long on average sun shines in December?
When is the lowest UV index in Adelphi?
What is the UV index reading in December?
Average temperature in December
Adelphi, MD
- Average high temperature in December: 45.3°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 (39.7°F).
- Average low temperature in December: 33.3°F
The month with the highest average low temperature is July (69.6°F).
The coldest month (with the lowest average low temperature) is January (27.1°F).
Average pressure in December
Adelphi, 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 (29.95"Hg).
Average wind speed in December
Adelphi, MD
- Average wind speed in December: 7.1mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Adelphi, MD
- Average humidity in December: 75%
The months with the highest relative humidity are May, October and December (75%).
The month with the lowest relative humidity is July (69%).
Average rainfall in December
Adelphi, MD
- Average rainfall in December: 2.44"
The wettest month (with the highest rainfall) is August (3.86").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in December
Adelphi, MD
- Average rainfall days in December: 10.4 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is November (8.5 days).
Average snowfall in December
Adelphi, MD
- Average snowfall in December: 1.34"
The month with the highest snowfall is January (2.87").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Adelphi, 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
Adelphi, MD
- Average daylight in December: 9h and 3min
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 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
Adelphi, MD
- Average sunshine days in December: 17.7 days
The month with the most sunshine days is November (19.5 days).
The month with the least sunshine days is May (12 days).
Average UV index in December
Adelphi, 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
Adelphi, MD
- Average cloud cover in December: 46
The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Adelphi, MD
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Adelphi, Maryland, USA
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