December weather forecastAllentown, PA

December
Weather in December
The last month of the year in Allentown ushers in the start of the chilly winter season. Conducive weather conditions prevail for snowfall, which measures up to 2.28" (58mm), marking the arrival of the winter wonderland. Although the cold might seem daunting, the festive mood fills the air, with snowy landscapes adding to the city's holiday charm. The drop in temperature does not deter the festive spirit, and Allentonians welcome the New Year amidst the winter chill.Temperature
With the onset of December, Allentown's average high-temperature adjusts, receding from November's chilly 49.8°F (9.9°C) to a wintry 40.1°F (4.5°C). Allentown observes an average nighttime low-temperature of 28.9°F (-1.7°C) during the month of December.Humidity
In Allentown, the average relative humidity in December is 81%.Rainfall
In Allentown, in December, it is raining for 9.2 days, with typically 2.32" (59mm) of accumulated precipitation. In Allentown, during the entire year, the rain falls for 145.1 days and collects up to 27.24" (692mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Allentown, in December, snow falls for 2.5 days, with typically accumulated 2.28" (58mm) of snow. In Allentown, during the entire year, snow falls for 20.4 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.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 4:45 pm EST.
Sunshine
The average sunshine in December is 4.7h.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 reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The average daily UV index of 2 in December transforms into the following instructions:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Allentown, PA
- Average high temperature in December: 40.1°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 (34°F).
- Average low temperature in December: 28.9°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
Allentown, 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
Allentown, PA
- Average wind speed in December: 7.5mph
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
Allentown, 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
Allentown, PA
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is July (3.03").
The driest month (with the least rainfall) is September (1.61").
Average rainfall days in December
Allentown, PA
- Average rainfall days in December: 9.2 days
The month with the highest number of rainy days is May (16.9 days).
The month with the least rainy days is January (6.7 days).
Average snowfall in December
Allentown, PA
- Average snowfall in December: 2.28"
The month with the highest snowfall is March (4.37").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Allentown, PA
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is February (6.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Allentown, 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: 4h and 42min
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 24min).
Average sunshine days in December
Allentown, PA
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is January (20.5 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in December
Allentown, PA
- Average UV index in December: 2
The months with the highest UV index are 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
Allentown, PA
- Average cloud cover in December: 51
The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is July (Cloud cover 34).
Average visibility in December
Allentown, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, July and November (6mi).
The months with the lowest visibility are January, February, March, May, June, August, September, October and December (5mi).





