December weather forecast
Mount Rainier, MD

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Weather in December

December marks the official onset of winter in Mount Rainier, characterized by colder temperatures and increased precipitation compared to the preceding month. The city witnesses a dip in the temperature scale, ranging between 34.3°F (1.3°C) and 45.5°F (7.5°C). As the year draws to a close, it brings about the shortest daylight hours and fewest sunshine days, a reflection of the seasonal change. Although snowfall slightly increasess in December, the city won’t see a comparable level until the subsequent January. Consequently, December weather in Mount Rainier helps to usher in the new year under a canopy of clouds and a blanket of white snow.

Temperature

As December commences in Mount Rainier, the average high-temperature subtly reduces, transitioning from a cool 54.1°F (12.3°C) in November to a chilly 45.5°F (7.5°C). Mount Rainier, in the month of December, anticipates a consistent average low-temperature of 34.3°F (1.3°C).

Humidity

The months with the highest humidity are May, October and December, with an average relative humidity of 76%.

Rainfall

In Mount Rainier, Maryland, in December, during 9.8 rainfall days, 2.6" (66mm) of precipitation is typically accumulated. Throughout the year, there are 157.9 rainfall days, and 31.14" (791mm) of precipitation is accumulated.

Snowfall

Months with snowfall in Mount Rainier are January through April and December. December is the first month it typically snows in Mount Rainier. Throughout December, in the average 2.4 snowfall days, it receives 0.67" (17mm) of snow. Throughout the year, there are 13.5 snowfall days, and 7.2" (183mm) of snow is accumulated.

Daylight

December has the shortest days of the year in Mount Rainier, Maryland, with an average of 9h and 30min of daylight.
On the first day of December in Mount Rainier, sunrise is at 7:08 am and sunset at 4:46 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 4:55 pm EST.

Sunshine

The average sunshine in December in Mount Rainier, Maryland, is 5.1h.

UV index

The months with the lowest UV index are January and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for ordinary individuals.
Note: The maximum UV index, 2 during December, leads to the following recommendations:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Opt for tightly woven and loose clothing to enhance protection from the Sun. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
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Frequently asked questions

What is the temperature in December in Mount Rainier?

In December, in Mount Rainier, the average high-temperature is 45.5°F (7.5°C), and the average low-temperature is 34.3°F (1.3°C). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, is evaluated at 93.2°F (34°C).

What are the most humid months in Mount Rainier?

The months with the highest humidity in Mount Rainier, Maryland, are May, October and December, with an average relative humidity of 76%.

What is the average humidity in December in Mount Rainier?

In December, the average relative humidity is 76%.

How much does it rain in Mount Rainier in December?

In Mount Rainier, in December, it is raining for 9.8 days, with typically 2.6" (66mm) of accumulated precipitation.

When does it start snowing in Mount Rainier?

December is the first month it typically snows in Mount Rainier. Throughout December, in the average 2.4 snowfall days, it receives 0.67" (17mm) of snow.

What is the month with the shortest days in Mount Rainier?

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

What is the average length of the day in December in Mount Rainier?

In December, the average day length in Mount Rainier is 9h and 29min.

When is the sunrise / sunset in December in Mount Rainier?

In December, on the first day of the month, sunrise is at 7:08 am and sunset at 4:46 pm. On the last day of the month, in Mount Rainier, sunrise is at 7:26 am and sunset at 4:55 pm EST.

How long on average sun shines in December in Mount Rainier?

In Mount Rainier, the average sunshine duration in December is 5.1h.

What are the months with the lowest UV index in Mount Rainier?

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

What is the UV index intensity in December in Mount Rainier?

In Mount Rainier, Maryland, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to Sun's UV rays.
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
Mount Rainier, MD

Average temperature in December - Mount Rainier, MD
  • Average high temperature in December: 45.5°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 (39.9°F).

  • Average low temperature in December: 34.3°F

The month with the highest average low temperature is July (70°F).
The coldest month (with the lowest average low temperature) is January (27.7°F).

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Average pressure in December
Mount Rainier, MD

Average pressure in December - Mount Rainier, 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).

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Average wind speed in December
Mount Rainier, MD

Average wind speed in December - Mount Rainier, MD
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

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Average humidity in December
Mount Rainier, MD

Average humidity in December - Mount Rainier, MD
  • Average humidity in December: 76%

The months with the highest relative humidity are May, October and December (76%).
The months with the lowest relative humidity are April and July (71%).

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Average rainfall in December
Mount Rainier, MD

Average rainfall in December - Mount Rainier, MD
  • Average rainfall in December: 2.6"

The wettest month (with the highest rainfall) is August (3.58").
The driest month (with the least rainfall) is January (2.01").

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Average rainfall days in December
Mount Rainier, MD

Average rainfall days in December - Mount Rainier, MD
  • Average rainfall days in December: 9.8 days

The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is November (9 days).

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Average snowfall in December
Mount Rainier, MD

Average snowfall in December - Mount Rainier, MD
  • Average snowfall in December: 0.67"

The month with the highest snowfall is January (2.6").
The months with the least snowfall are May, June, July, August, September, October and November (0").

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Average snowfall days in December
Mount Rainier, MD

Average snowfall days in December - Mount Rainier, MD
  • Average snowfall days in December: 2.4 days

The month with the highest number of snowfall days is January (4.1 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in December /
Average sunshine in December
Mount Rainier, MD

Average daylight in December / Average sunshine in December - Mount Rainier, 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 54min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).

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Average sunshine days in December
Mount Rainier, MD

Average sunshine days in December - Mount Rainier, MD
  • Average sunshine days in December: 18.1 days

The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (11.8 days).

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Average UV index in December
Mount Rainier, MD

Average UV index in December - Mount Rainier, 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).

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Average cloud cover in December
Mount Rainier, MD

Average cloud cover in December - Mount Rainier, MD
  • Average cloud cover in December: 45

The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).

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Average visibility in December
Mount Rainier, MD

Average visibility in December - Mount Rainier, 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).

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Mount Rainier, Maryland, USA

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