December weather forecastMerryman Heights, MD
December
Weather in December
The first month of the winter, December, is still a chilly month in Merryman Heights, Maryland, with an average temperature ranging between max 43.5°F (6.4°C) and min 31.5°F (-0.3°C).Temperature
The average high-temperature shows a slight dip in December, from November's fresh 52.3°F (11.3°C) to a frosty 43.5°F (6.4°C). Throughout December, Merryman Heights witnesses a consistent average low-temperature of 31.5°F (-0.3°C).Humidity
The average relative humidity in December is 77%.Rainfall
In Merryman Heights, 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
Months with snowfall are January through May, November and December. In Merryman Heights, in December, during 3.2 snowfall days, 1.54" (39mm) of snow is typically accumulated. In Merryman Heights, during the entire year, snow falls for 18.7 days and aggregates up to 9.96" (253mm) of snow.Daylight
December has the shortest days of the year in Merryman Heights, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:09 am and sunset at 4:44 pm. On the last day of December, sunrise is at 7:27 am and sunset at 4:54 pm EST.
Sunshine
In Merryman Heights, 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 estimate of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for the average person.Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Babies, children, and those with sensitive skin should always avoid extended periods in the sun. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, MD
- 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 6min
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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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
Merryman Heights, 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).
