December weather forecastChester, PA
December
Weather in December
Chester, Pennsylvania welcomes December with winter's cool embrace. This month receives the most snowfall at about 0.91" (23mm). Despite the dark, cold days, the city is lit up by holiday lights, creating a festive atmosphere. It is a time of quietness and calm, as Chester wraps up the year awaiting another round of changing seasons.Temperature
In Chester, entering December brings a subtle temperature decrement, reducing from November's fresh 52.7°F (11.5°C) to a frosty 44.1°F (6.7°C). Throughout the month of December, Chester expects an average low of 32.9°F (0.5°C).Humidity
The months with the highest humidity are February, October and December, with an average relative humidity of 77%.Rainfall
In December, the rain falls for 8.7 days. Throughout December, 2.32" (59mm) of precipitation is accumulated. In Chester, during the entire year, the rain falls for 148.4 days and collects up to 25.94" (659mm) of precipitation.Snowfall
Months with snowfall are January through May, November and December. In Chester, in December, during 1.5 snowfall days, 0.91" (23mm) of snow is typically accumulated. In Chester, during the entire year, snow falls for 12.6 days and aggregates up to 7.28" (185mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:04 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:46 pm EST.
Sunshine
In Chester, the average sunshine in December is 5.1h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: A typical high UV index of 2 in December suggests the following recommendations:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear. Take heed! The reflection of snow can intensify the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Chester, PA
- Average high temperature in December: 44.1°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in December: 32.9°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in December
Chester, 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
Chester, PA
- Average wind speed in December: 7.9mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in December
Chester, PA
- Average humidity in December: 77%
The months with the highest relative humidity are February, October and December (77%).
The month with the lowest relative humidity is April (71%).
Average rainfall in December
Chester, PA
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is August (3.11").
The driest month (with the least rainfall) is January (1.61").
Average rainfall days in December
Chester, PA
- Average rainfall days in December: 8.7 days
The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (7.1 days).
Average snowfall in December
Chester, PA
- Average snowfall in December: 0.91"
The month with the highest snowfall is March (2.32").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Chester, PA
- Average snowfall days in December: 1.5 days
The month with the highest number of snowfall days is February (3.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Chester, 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: 5h and 6min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
Average sunshine days in December
Chester, PA
- Average sunshine days in December: 20.5 days
The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is July (11.3 days).
Average UV index in December
Chester, 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, November and December (UV index 2).
Average cloud cover in December
Chester, PA
- Average cloud cover in December: 45
The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in December
Chester, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





