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
Transition from November to December is accompanied by a temperature drop, with average high-temperatures decreasing from a cool 51.4°F (10.8°C) to an icy 42.3°F (5.7°C). Rocky Hill, during December nights, observes an average temperature of 31.1°F (-0.5°C).Humidity
The average relative humidity in December is 78%.Rainfall
In December, the rain falls for 7.7 days. Throughout December, 1.14" (29mm) of precipitation is accumulated. In Rocky Hill, during the entire year, the rain falls for 124.6 days and collects up to 14.25" (362mm) of precipitation.Snowfall
Months with snowfall are January through May, November and December. In Rocky Hill, in December, snow falls for 2.2 days, with typically accumulated 0.79" (20mm) of snow. In Rocky Hill, Pennsylvania, during the entire year, snow falls for 18.5 days and aggregates up to 5.51" (140mm) 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 December in Rocky Hill, sunrise is at 7:05 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:47 pm EST.
Sunshine
In Rocky Hill, the average sunshine in December is 4.8h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum daily UV index, 2 in December, converts into the following recommendations:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Direct Sun exposure should be minimized especially during midday when radiation is most intense. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. 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
How cold is it in December?
What is the average humidity in December?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Rocky Hill have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Rocky Hill, PA
- Average high temperature in December: 42.3°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in December: 31.1°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Rocky Hill, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Rocky Hill, PA
- Average wind speed in December: 7.9mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in December
Rocky Hill, PA
- Average humidity in December: 78%
The months with the highest relative humidity are February and October (79%).
The months with the lowest relative humidity are April and July (73%).
Average rainfall in December
Rocky Hill, PA
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is August (1.89").
The driest month (with the least rainfall) is January (0.79").
Average rainfall days in December
Rocky Hill, PA
- Average rainfall days in December: 7.7 days
The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is January (5 days).
Average snowfall in December
Rocky Hill, PA
- Average snowfall in December: 0.79"
The month with the highest snowfall is March (1.57").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Rocky Hill, PA
- Average snowfall days in December: 2.2 days
The month with the highest number of snowfall days is January (5.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Rocky Hill, PA
- 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 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 30min).
Average sunshine days in December
Rocky Hill, PA
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is November (21.7 days).
The month with the least sunshine days is June (13.3 days).
Average UV index in December
Rocky Hill, PA
- 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, March, November and December (UV index 2).
Average cloud cover in December
Rocky Hill, PA
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Rocky Hill, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
Rocky Hill, Pennsylvania, USA
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