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
December brings a decrease in the average high-temperature, shifting from a fresh 50°F (10°C) in November to a wintry 40.1°F (4.5°C). An average low-temperature of 28.8°F (-1.8°C) is noted during the nights in December.Humidity
In December, the average relative humidity is 80%.Rainfall
In Bethlehem, during December, the rain falls for 10.7 days and regularly aggregates up to 2.24" (57mm) of precipitation. Throughout the year, there are 153 rainfall days, and 26.81" (681mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 4.8 days. Throughout December, 2.48" (63mm) of snow is accumulated. In Bethlehem, during the entire year, snow falls for 26.7 days and aggregates up to 14.49" (368mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:06 am and sunset at 4:35 pm. On the last day of December, sunrise is at 7:25 am and sunset at 4:44 pm EST.
Sunshine
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. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for the average person.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
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?
How many hours of daylight does Bethlehem have in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Bethlehem have in December?
What is the month with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Bethlehem, PA
- Average high temperature in December: 40.1°F
The warmest month (with the highest average high temperature) is July (83.5°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in December: 28.8°F
The month with the highest average low temperature is July (63.5°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in December
Bethlehem, PA
- Average pressure in December: 30.09"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
Bethlehem, PA
- Average wind speed in December: 7.6mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in December
Bethlehem, PA
- Average humidity in December: 80%
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
Bethlehem, PA
- Average rainfall in December: 2.24"
The wettest month (with the highest rainfall) is July (2.91").
The driest month (with the least rainfall) is September (1.57").
Average rainfall days in December
Bethlehem, PA
- Average rainfall days in December: 10.7 days
The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in December
Bethlehem, PA
- Average snowfall in December: 2.48"
The month with the highest snowfall is March (4.13").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Bethlehem, PA
- Average snowfall days in December: 4.8 days
The months with the highest number of snowfall days are January and February (7.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Bethlehem, 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 18min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Bethlehem, PA
- Average sunshine days in December: 17.2 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
Bethlehem, PA
- Average UV index in December: 2
The months with the highest UV index are May, June and July (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
Bethlehem, PA
- Average cloud cover in December: 50
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 34).
Average visibility in December
Bethlehem, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, June and November (6mi).
The months with the lowest visibility are January, February, March, May, July, August, September, October and December (5mi).
Bethlehem, Pennsylvania, USA
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