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 signifies a gentle decline in Marriottsville's average high-temperature, easing from a cool 52.3°F (11.3°C) in November to a frosty 43.5°F (6.4°C). An average nighttime temperature of 31.5°F (-0.3°C) is observed during December.Humidity
In Marriottsville, the average relative humidity in December is 77%.Rainfall
In Marriottsville, in December, during 10.5 rainfall days, 2.4" (61mm) of precipitation is typically accumulated. Throughout the year, there are 159 rainfall days, and 31.61" (803mm) of precipitation is accumulated.Snowfall
January through May, November and December are months with snowfall. In December, it is snowing for 3.2 days. Throughout December, 1.54" (39mm) of snow is accumulated. Throughout the year, there are 18.7 snowfall days, and 9.96" (253mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 30min of daylight.On the first day of December, sunrise is at 7:09 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:54 pm EST.
Sunshine
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 reading of 2, and below, represents a low health risk from exposure to the Sun's UV rays for the ordinary person.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What is the average humidity in December?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Marriottsville have in December?
What is the month with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Marriottsville, MD
- Average high temperature in December: 43.5°F
The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (37.6°F).
- Average low temperature in December: 31.5°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in December
Marriottsville, 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
Marriottsville, MD
- Average wind speed in December: 8mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).
Average humidity in December
Marriottsville, MD
- Average humidity in December: 77%
The month with the highest relative humidity is May (79%).
The months with the lowest relative humidity are April and July (74%).
Average rainfall in December
Marriottsville, MD
- Average rainfall in December: 2.4"
The wettest month (with the highest rainfall) is August (3.9").
The driest month (with the least rainfall) is February (1.97").
Average rainfall days in December
Marriottsville, MD
- Average rainfall days in December: 10.5 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is January (8.6 days).
Average snowfall in December
Marriottsville, MD
- Average snowfall in December: 1.54"
The month with the highest snowfall is March (2.8").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Marriottsville, MD
- Average snowfall days in December: 3.2 days
The month with the highest number of snowfall days is January (5.6 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Marriottsville, 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 1min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 48min).
Average sunshine days in December
Marriottsville, MD
- Average sunshine days in December: 17.4 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is May (11.2 days).
Average UV index in December
Marriottsville, 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, February, November and December (UV index 2).
Average cloud cover in December
Marriottsville, MD
- Average cloud cover in December: 46
The month with the most cloud cover is March (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in December
Marriottsville, 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).
Marriottsville, Maryland, USA
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