December weather forecast
Rockville, RI

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Weather in December

December, the first month of the winter in Rockville, is also an icy month, with an average temperature fluctuating between 30.4°F (-0.9°C) and 40.6°F (4.8°C).

Temperature

With December's arrival, Rockville's weather changes as the average high-temperature falls from a cool 50.2°F (10.1°C) in November to a wintry 40.6°F (4.8°C). Rockville experiences an average temperature drop to a freezing cold 30.4°F (-0.9°C) during December nights.

Humidity

In Rockville, Rhode Island, the average relative humidity in December is 76%.

Rainfall

December is the month with the most rainfall. Rain falls for 12 days and accumulates 3.7" (94mm) of precipitation.

Snowfall

January through May, November and December are months with snowfall. In Rockville, during December, snow falls for 4.8 days and regularly aggregates up to 1.5" (38mm) of snow. Throughout the year, in Rockville, there are 27.9 snowfall days, and 12.2" (310mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 9h and 12min of daylight.
On the first day of December, sunrise is at 6:54 am and sunset at 4:17 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:27 pm EST.

Sunshine

The average sunshine in December in Rockville is 4.8h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: A typical high UV index of 2 in December suggests the following recommendations:
Prolonged sun exposure generally does not trouble most people. However, it is vital to ensure protection for babies, children, and individuals with sensitive skin. It's recommended to limit sun exposure when its radiation is at its peak during midday. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Updated: Jul 27, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

December temperatures vary between a high-temperature of 40.6°F (4.8°C) and a low-temperature of 30.4°F (-0.9°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, in July is calculated to be 86°F (30°C).

What is the average humidity in December?

In Rockville, the average relative humidity in December is 76%.

What is the rainiest month?

December is the month with the most rainfall. Rain falls for 12 days and accumulates 3.7" (94mm) of precipitation.

How many days does it rain in December?

In Rockville, during December, the rain falls for 12 days and regularly aggregates up to 3.7" (94mm) of precipitation.

How much does it snow in December?

In Rockville, in December, during 4.8 snowfall days, 1.5" (38mm) of snow is typically accumulated.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 12min of daylight.

What is the average length of the day in December?

In December, the average day length is 9h and 14min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:54 am and sunset at 4:17 pm. On the last day of the month, sunrise is at 7:13 am and sunset at 4:27 pm EST.

How long on average sun shines in December?

In Rockville, Rhode Island, the average sunshine duration in December is 4.8h.

What are the months with the lowest UV index?

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

How high is the UV index in December?

The average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from 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
Rockville, RI

Average temperature in December - Rockville, RI
  • Average high temperature in December: 40.6°F

The warmest month (with the highest average high temperature) is July (80.6°F).
The month with the lowest average high temperature is January (35.1°F).

  • Average low temperature in December: 30.4°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).

Average pressure in December
Rockville, RI

Average pressure in December - Rockville, RI
  • Average pressure in December: 30.04"Hg

The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Rockville, RI

Average wind speed in December - Rockville, RI
  • Average wind speed in December: 9.4mph

The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity in December
Rockville, RI

Average humidity in December - Rockville, RI
  • Average humidity in December: 76%

The month with the highest relative humidity is June (80%).
The month with the lowest relative humidity is April (73%).

Average rainfall in December
Rockville, RI

Average rainfall in December - Rockville, RI
  • Average rainfall in December: 3.7"

The wettest month (with the highest rainfall) is December (3.7").
The driest month (with the least rainfall) is September (1.57").

Average rainfall days in December
Rockville, RI

Average rainfall days in December - Rockville, RI
  • Average rainfall days in December: 12 days

The month with the highest number of rainy days is May (16.9 days).
The month with the least rainy days is January (9.1 days).

Average snowfall in December
Rockville, RI

Average snowfall in December - Rockville, RI
  • Average snowfall in December: 1.5"

The month with the highest snowfall is March (3.54").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Rockville, RI

Average snowfall days in December - Rockville, RI
  • Average snowfall days in December: 4.8 days

The month with the highest number of snowfall days is February (7.4 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
Rockville, RI

Average daylight in December / Average sunshine in December - Rockville, RI
  • Average daylight in December: 9h and 1min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in December: 4h and 5min

The months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in December
Rockville, RI

Average sunshine days in December - Rockville, RI
  • Average sunshine days in December: 15.8 days

The month with the most sunshine days is November (17.3 days).
The month with the least sunshine days is June (10.9 days).

Average UV index in December
Rockville, RI

Average UV index in December - Rockville, RI
  • Average UV index in December: 2

The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

Average cloud cover in December
Rockville, RI

Average cloud cover in December - Rockville, RI
  • Average cloud cover in December: 47

The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 32).

Average visibility in December
Rockville, RI

Average visibility in December - Rockville, RI
  • 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).

Rockville, Rhode Island, USA

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