December weather forecastRockville, RI
December
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.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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: 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: 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: 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: 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: 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: 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: 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: 9h and 12min
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 48min
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: 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: 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: 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: 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).





