December weather forecast
South River Heights, MD

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Weather in December

The first month of the winter, December, is also a frosty month in South River Heights, Maryland, with an average temperature varying between 36.5°F (2.5°C) and 46°F (7.8°C).

Temperature

December ushers in a minor alteration in South River Heights's climate, with the average high-temperature moving from November's fresh 54.5°F (12.5°C) to a chilly 46°F (7.8°C). During December, the temperature is averaged to a low of 36.5°F (2.5°C) at night.

Humidity

In December, the average relative humidity is 75%.

Rainfall

In December, the rain falls for 7.4 days. Throughout December, 0.67" (17mm) of precipitation is accumulated. In South River Heights, during the entire year, the rain falls for 120.4 days and collects up to 10.47" (266mm) of precipitation.

Snowfall

Months with snowfall are January through March, November and December. In South River Heights, in December, during 1.5 snowfall days, 0.12" (3mm) of snow is typically accumulated. Throughout the year, there are 8.3 snowfall days, and 1.22" (31mm) 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 7:06 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 4:54 pm EST.

Sunshine

In December, the average sunshine is 5.2h.

UV index

The months with the lowest UV index are January, February and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: In December, the maximum UV index of 2 suggests this advice:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.

Frequently asked questions

What is the average December temperature?

In South River Heights, 46°F (7.8°C) is the average high-temperature and 36.5°F (2.5°C) is the average low-temperature during December. In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines air temperature and relative humidity, is evaluated at 89.6°F (32°C).

What is the average humidity in December?

In South River Heights, the average relative humidity in December is 75%.

How many days does it rain in December in South River Heights?

In December, the rain falls for 7.4 days. Throughout December, 0.67" (17mm) of precipitation is accumulated.

How much does it snow in December?

In South River Heights, during December, snow falls for 1.5 days and regularly aggregates up to 0.12" (3mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 30min of daylight.

What is the average length of the day in December?

In South River Heights, the average day length in December is 9h and 29min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:06 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 4:54 pm EST.

How many hours of sunshine does South River Heights have in December?

In South River Heights, the average sunshine duration in December is 5.2h.

What is the month with the lowest UV index?

The months with the lowest UV index are January, February and December, with an average maximum UV index of 2.

How high is the UV index in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to UV radiation.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
South River Heights, MD

Average temperature in December - South River Heights, MD
  • Average high temperature in December: 46°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 (40.3°F).

  • Average low temperature in December: 36.5°F

The month with the highest average low temperature is July (72°F).
The coldest month (with the lowest average low temperature) is January (29.8°F).

Average pressure in December
South River Heights, MD

Average pressure in December - South River Heights, MD
  • Average pressure in December: 30.11"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
South River Heights, MD

Average wind speed in December - South River Heights, MD
  • Average wind speed in December: 9.3mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).

Average humidity in December
South River Heights, MD

Average humidity in December - South River Heights, MD
  • Average humidity in December: 75%

The month with the highest relative humidity is May (78%).
The months with the lowest relative humidity are January, March, April and November (72%).

Average rainfall in December
South River Heights, MD

Average rainfall in December - South River Heights, MD
  • Average rainfall in December: 0.67"

The wettest month (with the highest rainfall) is August (1.69").
The driest month (with the least rainfall) is January (0.47").

Average rainfall days in December
South River Heights, MD

Average rainfall days in December - South River Heights, MD
  • Average rainfall days in December: 7.4 days

The months with the highest number of rainy days are July and August (14.3 days).
The month with the least rainy days is November (5.3 days).

Average snowfall in December
South River Heights, MD

Average snowfall in December - South River Heights, MD
  • Average snowfall in December: 0.12"

The month with the highest snowfall is January (0.67").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
South River Heights, MD

Average snowfall days in December - South River Heights, MD
  • Average snowfall days in December: 1.5 days

The month with the highest number of snowfall days is February (2.5 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
South River Heights, MD

Average daylight in December / Average sunshine in December - South River Heights, 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 48min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).

Average sunshine days in December
South River Heights, MD

Average sunshine days in December - South River Heights, MD
  • Average sunshine days in December: 21.5 days

The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is August (13.8 days).

Average UV index in December
South River Heights, MD

Average UV index in December - South River 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 and December (UV index 2).

Average cloud cover in December
South River Heights, MD

Average cloud cover in December - South River Heights, MD
  • Average cloud cover in December: 44

The months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 28).

Average visibility in December
South River Heights, MD

Average visibility in December - South River 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).

South River Heights, Maryland, USA

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