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 onset of December results in a decrease in the average high-temperature, receding from a chilly 48°F (8.9°C) in November to an icy 38.5°F (3.6°C). Waterfall records an average low-temperature of 27.3°F (-2.6°C) throughout the month of December.Humidity
In December, the average relative humidity in Waterfall, Pennsylvania, is 81%.Rainfall
In Waterfall, during December, the rain falls for 10.2 days and regularly aggregates up to 1.57" (40mm) of precipitation. Throughout the year, there are 146.6 rainfall days, and 19.84" (504mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In December, in Waterfall, it is snowing for 6.7 days. Throughout December, 2.2" (56mm) of snow is accumulated. Throughout the year, there are 37.4 snowfall days, and 14.61" (371mm) of snow is accumulated.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year in Waterfall, Pennsylvania.On the first day of the month, sunrise is at 7:15 am and sunset at 4:47 pm. On the last day of December, sunrise is at 7:34 am and sunset at 4:56 pm EST.
Sunshine
In December, the average sunshine is 4.4h.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 estimate of 2, and below, represents a minimal health vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: The UV index of 2 in December translates into these instructions:
Most people face no serious problems with extended sun exposure, but those with fair skin, infants, and children always need protection. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by 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 many days does it rain in December?
How much does it snow in December?
What is the month with the shortest days in Waterfall?
What is the average length of the day in December in Waterfall?
When are sunrise and sunset in December?
How long on average sun shines in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Waterfall, PA
- Average high temperature in December: 38.5°F
The warmest month (with the highest average high temperature) is July (82.4°F).
The month with the lowest average high temperature is January (32.5°F).
- Average low temperature in December: 27.3°F
The month with the highest average low temperature is July (60.6°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in December
Waterfall, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Waterfall, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in December
Waterfall, PA
- Average humidity in December: 81%
The month with the highest relative humidity is February (82%).
The months with the lowest relative humidity are April and July (76%).
Average rainfall in December
Waterfall, PA
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is May (2.36").
The driest month (with the least rainfall) is November (1.18").
Average rainfall days in December
Waterfall, PA
- Average rainfall days in December: 10.2 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (7.5 days).
Average snowfall in December
Waterfall, PA
- Average snowfall in December: 2.2"
The month with the highest snowfall is February (3.74").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Waterfall, PA
- Average snowfall days in December: 6.7 days
The month with the highest number of snowfall days is January (10.9 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
Waterfall, 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 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Waterfall, PA
- Average sunshine days in December: 16.8 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (11 days).
Average UV index in December
Waterfall, PA
- Average UV index in December: 2
The month with the highest UV index is June (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
Waterfall, PA
- Average cloud cover in December: 54
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Waterfall, PA
- Average visibility in December: 5mi
The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).
Waterfall, Pennsylvania, USA
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