December weather forecastRook, PA
December
Weather in December
The first month of the winter, December, is still a cold month in Rook, Pennsylvania, with an average temperature ranging between min 28.2°F (-2.1°C) and max 39.7°F (4.3°C).Temperature
December shows a mild decline in the average high-temperature, falling from November's frosty 49.3°F (9.6°C) to a cold 39.7°F (4.3°C). Throughout the month of December, Rook observes an average nighttime temperature of 28.2°F (-2.1°C).Humidity
In Rook, the average relative humidity in December is 83%.Rainfall
In Rook, in December, it is raining for 10.7 days, with typically 2.09" (53mm) of accumulated precipitation. Throughout the year, there are 164 rainfall days, and 26.89" (683mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In Rook, during December, snow falls for 11.8 days and regularly aggregates up to 2.64" (67mm) of snow. Throughout the year, there are 53.3 snowfall days, and 13.27" (337mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:24 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 5:03 pm EST.
Sunshine
In Rook, the average sunshine in December is 3.3h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In December, the maximum UV index of 1 suggests these recommendations:
While most people can stay under the sun for an hour without burning, children must always be guarded against sun exposure. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rook, PA
- Average high temperature in December: 39.7°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in December: 28.2°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure in December
Rook, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Rook, PA
- Average wind speed in December: 7.3mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in December
Rook, PA
- Average humidity in December: 83%
The months with the highest relative humidity are January and February (84%).
The month with the lowest relative humidity is August (73%).
Average rainfall in December
Rook, PA
- Average rainfall in December: 2.09"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is November (1.61").
Average rainfall days in December
Rook, PA
- Average rainfall days in December: 10.7 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is January (8.5 days).
Average snowfall in December
Rook, PA
- Average snowfall in December: 2.64"
The month with the highest snowfall is January (3.46").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Rook, PA
- Average snowfall days in December: 11.8 days
The month with the highest number of snowfall days is January (16.3 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
Rook, PA
- Average daylight in December: 9h and 18min
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: 3h and 18min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).
Average sunshine days in December
Rook, PA
- Average sunshine days in December: 11 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is February (9.5 days).
Average UV index in December
Rook, PA
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Rook, PA
- Average cloud cover in December: 66
The month with the most cloud cover is January (Cloud cover 69).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Rook, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).





