Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December brings a drop in Rockville's average high-temperature, falling from a frosty 48.4°F (9.1°C) in November to a wintry 38.1°F (3.4°C). During the nights in December, the temperature averages to a freezing cold 27.1°F (-2.7°C).Humidity
The average relative humidity in December is 78%.Rainfall
In Rockville, in December, during 7 rainfall days, 0.79" (20mm) of precipitation is typically accumulated. Throughout the year, there are 105.6 rainfall days, and 9.84" (250mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, November and December. In Rockville, during December, snow falls for 3.5 days and regularly aggregates up to 0.67" (17mm) of snow. In Rockville, during the entire year, snow falls for 23.1 days and aggregates up to 4.69" (119mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 12min of daylight.On the first day of December, sunrise is at 6:58 am and sunset at 4:19 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 4:28 pm EST.
Sunshine
In December, the average sunshine in Rockville is 4.7h.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 reading of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for average individuals.Note: During December, 2 as the daily maximum UV index converts into the following advice:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold in Rockville?
What is the average humidity in December in Rockville?
How many days does it rain in December in Rockville?
How many days does it snow in December in Rockville?
What is the month with the shortest days in Rockville?
What is the average length of the day in December in Rockville?
When are sunrise and sunset in December in Rockville?
How long on average sun shines in December in Rockville?
What are the months with the lowest UV index in Rockville?
What is the UV index reading in December in Rockville?
Average temperature in December
Rockville, CT
- Average high temperature in December: 38.1°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (32.4°F).
- Average low temperature in December: 27.1°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in December
Rockville, CT
- Average pressure in December: 30.05"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, CT
- Average wind speed in December: 7.8mph
The windiest months (with the highest average wind speed) are January and March (8.2mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Rockville, CT
- Average humidity in December: 78%
The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (71%).
Average rainfall in December
Rockville, CT
- Average rainfall in December: 0.79"
The wettest months (with the highest rainfall) are May, June and July (1.1").
The driest month (with the least rainfall) is September (0.39").
Average rainfall days in December
Rockville, CT
- Average rainfall days in December: 7 days
The month with the highest number of rainy days is June (12.1 days).
The months with the least rainy days are January and February (5.5 days).
Average snowfall in December
Rockville, CT
- Average snowfall in December: 0.67"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Rockville, CT
- Average snowfall days in December: 3.5 days
The month with the highest number of snowfall days is February (6.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rockville, CT
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 4min
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 36min).
Average sunshine days in December
Rockville, CT
- Average sunshine days in December: 20.4 days
The month with the most sunshine days is January (21.9 days).
The month with the least sunshine days is June (15.7 days).
Average UV index in December
Rockville, CT
- 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, CT
- Average cloud cover in December: 48
The months with the most cloud cover are February and March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Rockville, CT
- Average visibility in December: 6mi
The months with the highest visibility are January, March, April, October, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August and September (5mi).
Rockville, Connecticut, USA
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