December weather forecastExton, PA
December
Weather in December
Closing the year in Exton, December brings a pronounced onset of winter, dropping the temperature between 31.1°F (-0.5°C) and 42.3°F (5.7°C). The city experiences increased snowfall with 0.79" (20mm) registered over more than two days of the month. As the days shorten further, the chilling winds add to the icy ambiance. Despite the cold, a fair amount of sunshine peeps through casting a shimmering glow on the snow-dusted cityscape. The month provides the city with a picturesque white Christmas, ending the year with a festive spirit.Temperature
The onset of December coincides with a reduction in the average high-temperature, falling from a fresh 51.4°F (10.8°C) in November to an icy 42.3°F (5.7°C). December brings an average low-temperature of 31.1°F (-0.5°C) to Exton.Humidity
The average relative humidity in December is 78%.Rainfall
In December, the rain falls for 7.7 days. Throughout December, 1.14" (29mm) of precipitation is accumulated. In Exton, during the entire year, the rain falls for 124.6 days and collects up to 14.25" (362mm) of precipitation.Snowfall
Months with snowfall are January through May, November and December. In December, it is snowing for 2.2 days. Throughout December, 0.79" (20mm) of snow is accumulated. In Exton, during the entire year, snow falls for 18.5 days and aggregates up to 5.51" (140mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:05 am and sunset at 4:37 pm. On the last day of December, sunrise is at 7:24 am and sunset at 4:47 pm EST.
Sunshine
In December, the average sunshine is 4.8h.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 hazard from exposure to the Sun's UV radiation for the ordinary person.Note: In December, a daily maximum UV index of 2 leads to the following instructions:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. To cut down UV radiation exposure by about half, sport a wide-brim hat. Keep in mind! Snow's reflective quality can nearly 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
Exton, PA
- Average high temperature in December: 42.3°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (36.1°F).
- Average low temperature in December: 31.1°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Exton, 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
Exton, PA
- Average wind speed in December: 7.9mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in December
Exton, PA
- Average humidity in December: 78%
The months with the highest relative humidity are February and October (79%).
The months with the lowest relative humidity are April and July (73%).
Average rainfall in December
Exton, PA
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is August (1.89").
The driest month (with the least rainfall) is January (0.79").
Average rainfall days in December
Exton, PA
- Average rainfall days in December: 7.7 days
The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is January (5 days).
Average snowfall in December
Exton, PA
- Average snowfall in December: 0.79"
The month with the highest snowfall is March (1.57").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Exton, PA
- Average snowfall days in December: 2.2 days
The month with the highest number of snowfall days is January (5.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Exton, PA
- Average daylight in December: 9h and 24min
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 48min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Exton, PA
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is November (21.7 days).
The month with the least sunshine days is June (13.3 days).
Average UV index in December
Exton, PA
- Average UV index in December: 2
The months with the highest UV index are May, June, July and August (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
Exton, PA
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Exton, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).
