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
The commencement of December indicates a gentle shift in the average high-temperature, receding from November's cool 51.8°F (11°C) to a frosty 43°F (6.1°C). The average temperature drops to a freezing cold 31.1°F (-0.5°C) during the night in the month of December.Humidity
In Rocky Hill, the average relative humidity in December is 78%.Rainfall
In December, in Rocky Hill, the rain falls for 8.2 days. Throughout December, 1.26" (32mm) of precipitation is accumulated. Throughout the year, there are 119.3 rainfall days, and 12.72" (323mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, November and December. In Rocky Hill, in December, snow falls for 2.7 days, with typically accumulated 0.75" (19mm) of snow. Throughout the year, there are 16.4 snowfall days, and 4.41" (112mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December in Rocky Hill, sunrise is at 7:02 am and sunset at 4:32 pm. On the last day of the month, sunrise is at 7:21 am and sunset at 4:42 pm EST.
Sunshine
The average sunshine in December is 5h.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 exposure to the Sun's UV radiation for the average person.Note: The maximum UV index of 2 during December translates into these guidelines:
Most people face no serious problems with extended sun exposure, but those with fair skin, infants, and children always need protection. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
How many days does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Rocky Hill have in December?
What time are sunrise and sunset in December in Rocky Hill?
How long on average sun shines in December?
What are the months with the lowest UV index?
What is the UV index intensity in December in Rocky Hill?
Average temperature in December
Rocky Hill, NJ
- Average high temperature in December: 43°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 (36.9°F).
- Average low temperature in December: 31.1°F
The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Rocky Hill, NJ
- Average pressure in December: 30.08"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Rocky Hill, NJ
- Average wind speed in December: 7.8mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Rocky Hill, NJ
- Average humidity in December: 78%
The month with the highest relative humidity is October (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in December
Rocky Hill, NJ
- Average rainfall in December: 1.26"
The wettest month (with the highest rainfall) is July (1.69").
The driest month (with the least rainfall) is September (0.67").
Average rainfall days in December
Rocky Hill, NJ
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is July (13.9 days).
The month with the least rainy days is January (6.1 days).
Average snowfall in December
Rocky Hill, NJ
- Average snowfall in December: 0.75"
The month with the highest snowfall is March (1.42").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Rocky Hill, NJ
- Average snowfall days in December: 2.7 days
The month with the highest number of snowfall days is January (4.6 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
Rocky Hill, NJ
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 5h and 0min
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 48min).
Average sunshine days in December
Rocky Hill, NJ
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is January (21.8 days).
The month with the least sunshine days is July (13.3 days).
Average UV index in December
Rocky Hill, NJ
- 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
Rocky Hill, NJ
- Average cloud cover in December: 47
The months with the most cloud cover are February, March and December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 33).
Average visibility in December
Rocky Hill, NJ
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
Rocky Hill, New Jersey, USA
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