December weather forecastHeather Heights, MD
December
Weather in December
The first month of the winter, December, is also a frosty month in Heather Heights, Maryland, with temperature in the range of an average high of 45.5°F (7.5°C) and an average low of 34.5°F (1.4°C).Temperature
Heather Heights's transition into December involves a gentle shift in temperature, receding from a fresh 54°F (12.2°C) in November to a chilly 45.5°F (7.5°C). Heather Heights records an average nighttime low of 34.5°F (1.4°C) in December.Humidity
In Heather Heights, the average relative humidity in December is 76%.Rainfall
In Heather Heights, Maryland, during December, the rain falls for 7.3 days and regularly aggregates up to 0.98" (25mm) of precipitation. Throughout the year, there are 107.5 rainfall days, and 10.67" (271mm) of precipitation is accumulated.Snowfall
January through March, November and December are months with snowfall. In Heather Heights, during December, snow falls for 1.4 days and regularly aggregates up to 0.24" (6mm) of snow. In Heather Heights, during the entire year, snow falls for 9.4 days and aggregates up to 1.73" (44mm) 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 7:05 am and sunset at 4:41 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:51 pm EST.
Sunshine
The average sunshine in December is 5.2h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: In December, the maximum UV index of 2 suggests these recommendations:
Despite the majority tolerating prolonged sun exposure, those with sensitive skin, infants, and children demand continual protection. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days. Be alert! Nearly double the UV rays from the Sun can be reflected by snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Heather Heights, MD
- Average high temperature in December: 45.5°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (39.2°F).
- Average low temperature in December: 34.5°F
The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (27.9°F).
Average pressure in December
Heather Heights, MD
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Heather Heights, MD
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is February (9.4mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in December
Heather Heights, MD
- Average humidity in December: 76%
The month with the highest relative humidity is May (79%).
The months with the lowest relative humidity are January, March, April and November (74%).
Average rainfall in December
Heather Heights, MD
- Average rainfall in December: 0.98"
The wettest month (with the highest rainfall) is August (1.42").
The driest month (with the least rainfall) is September (0.43").
Average rainfall days in December
Heather Heights, MD
- Average rainfall days in December: 7.3 days
The month with the highest number of rainy days is July (12.4 days).
The month with the least rainy days is November (5.6 days).
Average snowfall in December
Heather Heights, MD
- Average snowfall in December: 0.24"
The month with the highest snowfall is January (0.59").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Heather Heights, MD
- Average snowfall days in December: 1.4 days
The month with the highest number of snowfall days is January (3.1 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
Heather Heights, 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 12min
The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).
Average sunshine days in December
Heather Heights, MD
- Average sunshine days in December: 21.8 days
The month with the most sunshine days is January (22.3 days).
The month with the least sunshine days is July (15.1 days).
Average UV index in December
Heather 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 and December (UV index 2).
Average cloud cover in December
Heather Heights, 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
Heather Heights, 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).





