December weather forecast
Rocky Ridge, MD

Share

Weather in December

December, the first month of the winter in Rocky Ridge, is still a cold month, with an average temperature varying between 30.2°F (-1°C) and 42.1°F (5.6°C).

Temperature

Rocky Ridge's transition into December involves a gentle shift in temperature, receding from a cool 50.9°F (10.5°C) in November to a wintry 42.1°F (5.6°C). The average low-temperature of 30.2°F (-1°C) is witnessed during December.

Humidity

In December, the average relative humidity is 79%.

Rainfall

In Rocky Ridge, in December, it is raining for 10.8 days, with typically 2.4" (61mm) of accumulated precipitation. Throughout the year, in Rocky Ridge, there are 164.1 rainfall days, and 31.97" (812mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall. In Rocky Ridge, in December, during 4.8 snowfall days, 2.13" (54mm) of snow is typically accumulated. In Rocky Ridge, during the entire year, snow falls for 26.7 days and aggregates up to 14.13" (359mm) of snow.

Daylight

With an average of 9h and 24min of daylight, December has the shortest days of the year.
On the first day of the month, sunrise is at 7:11 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:29 am and sunset at 4:55 pm EST.

Sunshine

In Rocky Ridge, the average sunshine in December is 4.9h.

UV index

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.
Note: A maximum high UV index of 2 in December translates into the following recommendations:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Heads up! The UV radiation from the Sun can almost be doubled by snow reflection.

Frequently asked questions

How cold does it get in December?

The average high-temperature and low-temperature during December are 42.1°F (5.6°C) and 30.2°F (-1°C) respectively. In August, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which combines air temperature and relative humidity, is calculated to be 87.8°F (31°C).

What is the average humidity in December?

In Rocky Ridge, the average relative humidity in December is 79%.

How many days does it rain in December?

In Rocky Ridge, in December, during 10.8 rainfall days, 2.4" (61mm) of precipitation is typically accumulated.

How much does it snow in Rocky Ridge in December?

In December, in Rocky Ridge, it is snowing for 4.8 days. Throughout December, 2.13" (54mm) of snow is accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 24min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 26min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:11 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:55 pm EST.

How long on average sun shines in December?

In Rocky Ridge, the average sunshine duration in December is 4.9h.

What is the month with the lowest UV index?

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

What is the UV index intensity in December in Rocky Ridge?

The average daily maximum UV index in December is 2. A UV Index reading of 2, and below, represents a minimal hazard to health 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
Rocky Ridge, MD

Average temperature in December - Rocky Ridge, MD
  • Average high temperature in December: 42.1°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 (36.7°F).

  • Average low temperature in December: 30.2°F

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).

Average pressure in December
Rocky Ridge, MD

Average pressure in December - Rocky Ridge, 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 (29.95"Hg).

Average wind speed in December
Rocky Ridge, MD

Average wind speed in December - Rocky Ridge, MD
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).

Average humidity in December
Rocky Ridge, MD

Average humidity in December - Rocky Ridge, MD
  • Average humidity in December: 79%

The month with the highest relative humidity is October (80%).
The months with the lowest relative humidity are April and July (75%).

Average rainfall in December
Rocky Ridge, MD

Average rainfall in December - Rocky Ridge, MD
  • Average rainfall in December: 2.4"

The wettest month (with the highest rainfall) is May (3.5").
The driest month (with the least rainfall) is February (2.2").

Average rainfall days in December
Rocky Ridge, MD

Average rainfall days in December - Rocky Ridge, MD
  • Average rainfall days in December: 10.8 days

The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is January (8.7 days).

Average snowfall in December
Rocky Ridge, MD

Average snowfall in December - Rocky Ridge, MD
  • Average snowfall in December: 2.13"

The month with the highest snowfall is January (4.53").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Rocky Ridge, MD

Average snowfall days in December - Rocky Ridge, MD
  • Average snowfall days in December: 4.8 days

The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
Rocky Ridge, MD

Average daylight in December / Average sunshine in December - Rocky Ridge, MD
  • Average daylight in December: 9h and 2min

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: 4h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).

Average sunshine days in December
Rocky Ridge, MD

Average sunshine days in December - Rocky Ridge, MD
  • Average sunshine days in December: 16.8 days

The month with the most sunshine days is November (18.4 days).
The month with the least sunshine days is May (11.2 days).

Average UV index in December
Rocky Ridge, MD

Average UV index in December - Rocky Ridge, 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
Rocky Ridge, MD

Average cloud cover in December - Rocky Ridge, MD
  • Average cloud cover in December: 48

The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 32).

Average visibility in December
Rocky Ridge, MD

Average visibility in December - Rocky Ridge, MD
  • Average visibility in December: 5mi

The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).

Rocky Ridge, Maryland, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location