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
Onset of December witnesses a reduction in the average high-temperature, falling from a chilly 47.1°F (8.4°C) in November to an icy 37.2°F (2.9°C). Slippery Rock temperatures generally rest at a low of 26.2°F (-3.2°C) during the December nights.Humidity
The average relative humidity in December in Slippery Rock is 86%.Rainfall
In December, the rain falls for 10.7 days. Throughout December, 2.83" (72mm) of precipitation is accumulated. Throughout the year, there are 177.8 rainfall days, and 36.65" (931mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Slippery Rock, in December, during 15.6 snowfall days, 5.83" (148mm) of snow is typically accumulated. In Slippery Rock, during the entire year, snow falls for 75.3 days and aggregates up to 32.05" (814mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:26 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 7:45 am and sunset at 5:01 pm EST.
Sunshine
The average sunshine in December is 2.7h.UV index
The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for average individuals.Note: In December, a regular UV index of 1 translates into these guidelines:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Note this! The Sun's UV radiation can nearly be doubled by the reflection off snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How much does it rain in December?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Slippery Rock have in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Slippery Rock, PA
- Average high temperature in December: 37.2°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (31.3°F).
- Average low temperature in December: 26.2°F
The month with the highest average low temperature is July (60.1°F).
The coldest month (with the lowest average low temperature) is January (18.1°F).
Average pressure in December
Slippery Rock, 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
Slippery Rock, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.2mph).
Average humidity in December
Slippery Rock, PA
- Average humidity in December: 86%
The month with the highest relative humidity is February (88%).
The months with the lowest relative humidity are April, May, June, July and August (79%).
Average rainfall in December
Slippery Rock, PA
- Average rainfall in December: 2.83"
The wettest month (with the highest rainfall) is April (3.74").
The driest month (with the least rainfall) is November (2.36").
Average rainfall days in December
Slippery Rock, PA
- Average rainfall days in December: 10.7 days
The month with the highest number of rainy days is May (19.8 days).
The month with the least rainy days is January (8.1 days).
Average snowfall in December
Slippery Rock, PA
- Average snowfall in December: 5.83"
The month with the highest snowfall is January (8.54").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Slippery Rock, PA
- Average snowfall days in December: 15.6 days
The month with the highest number of snowfall days is January (19.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Slippery Rock, PA
- Average daylight in December: 9h and 2min
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: 2h and 4min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 2h and 18min).
Average sunshine days in December
Slippery Rock, PA
- Average sunshine days in December: 9.3 days
The month with the most sunshine days is November (13.1 days).
The month with the least sunshine days is February (6.3 days).
Average UV index in December
Slippery Rock, PA
- Average UV index in December: 1
The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Slippery Rock, PA
- Average cloud cover in December: 72
The month with the most cloud cover is January (Cloud cover 76).
The month with the least cloud cover is August (Cloud cover 38).
Average visibility in December
Slippery Rock, PA
- Average visibility in December: 4mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February and December (4mi).
Slippery Rock, Pennsylvania, USA
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