December weather forecastHillsdale, NJ
December
Weather in December
December, the first month of the winter in Hillsdale, is still a cold month, with an average temperature varying between 30.4°F (-0.9°C) and 40.8°F (4.9°C).Temperature
As December commences, the average high-temperature shows a reduction, transitioning from a fresh 50.7°F (10.4°C) in November to a cold 40.8°F (4.9°C). Hillsdale's nighttime temperature in December drops to an average of 30.4°F (-0.9°C).Humidity
February and December, with an average relative humidity of 78%, are the most humid months.Rainfall
December is the month with the most rainfall in Hillsdale. Rain falls for 10.6 days and accumulates 3.58" (91mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In December, it is snowing for 4.5 days. Throughout December, 2.05" (52mm) of snow is accumulated. In Hillsdale, during the entire year, snow falls for 28 days and aggregates up to 13.82" (351mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year in Hillsdale, New Jersey.On the first day of the month, sunrise is at 7:02 am and sunset at 4:28 pm. On the last day of December, in Hillsdale, sunrise is at 7:20 am and sunset at 4:38 pm EST.
Sunshine
In Hillsdale, the average sunshine in December is 4.7h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Hillsdale. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.Note: In December, the maximum UV index of 2 suggests this advice:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Hillsdale, NJ
- Average high temperature in December: 40.8°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 (35.2°F).
- Average low temperature in December: 30.4°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).
Average pressure in December
Hillsdale, NJ
- Average pressure in December: 30.07"Hg
The month with the highest atmospheric pressure is November (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Hillsdale, NJ
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in December
Hillsdale, NJ
- Average humidity in December: 78%
The months with the highest relative humidity are February and December (78%).
The month with the lowest relative humidity is August (70%).
Average rainfall in December
Hillsdale, NJ
- Average rainfall in December: 3.58"
The wettest month (with the highest rainfall) is December (3.58").
The driest month (with the least rainfall) is September (1.89").
Average rainfall days in December
Hillsdale, NJ
- Average rainfall days in December: 10.6 days
The months with the highest number of rainy days are May and July (16.8 days).
The month with the least rainy days is January (8.4 days).
Average snowfall in December
Hillsdale, NJ
- Average snowfall in December: 2.05"
The month with the highest snowfall is February (4.09").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Hillsdale, NJ
- Average snowfall days in December: 4.5 days
The month with the highest number of snowfall days is February (7.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Hillsdale, NJ
- Average daylight in December: 9h and 18min
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 18min).
- Average sunshine in December: 4h and 42min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Hillsdale, NJ
- Average sunshine days in December: 16.7 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is June (11.5 days).
Average UV index in December
Hillsdale, 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
Hillsdale, NJ
- Average cloud cover in December: 49
The month with the most cloud cover is March (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Hillsdale, 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).
