December weather forecastChatham, PA
December
Weather in December
The first month of the winter, December, is also a frosty month in Chatham, Pennsylvania, with temperature in the range of an average high of 43°F (6.1°C) and an average low of 31.5°F (-0.3°C).Temperature
Chatham's transition into December involves a shift in temperature, receding from a cool 52°F (11.1°C) in November to a chilly 43°F (6.1°C). Chatham's nighttime temperature during December is consistently averaged at a freezing cold 31.5°F (-0.3°C).Humidity
February, May, September, October and December, with an average relative humidity of 79%, are the most humid months.Rainfall
In December, the rain falls for 8.5 days. Throughout December, 1.22" (31mm) of precipitation is accumulated. In Chatham, during the entire year, the rain falls for 126.3 days and collects up to 14.25" (362mm) of precipitation.Snowfall
Months with snowfall are January through May, November and December. In Chatham, in December, snow falls for 2.1 days, with typically accumulated 0.59" (15mm) of snow. Throughout the year, there are 15.4 snowfall days, and 4.33" (110mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:06 am and sunset at 4:39 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 4:48 pm EST.
Sunshine
The average sunshine in December is 5h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.Note: In December, the maximum UV index of 2 transforms into these recommendations:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Chatham, PA
- Average high temperature in December: 43°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in December: 31.5°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (24.6°F).
Average pressure in December
Chatham, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Chatham, PA
- Average wind speed in December: 8.2mph
The windiest months (with the highest average wind speed) are February and March (8.8mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in December
Chatham, PA
- Average humidity in December: 79%
The months with the highest relative humidity are February, May, September, October and December (79%).
The months with the lowest relative humidity are March and April (75%).
Average rainfall in December
Chatham, PA
- Average rainfall in December: 1.22"
The wettest month (with the highest rainfall) is August (1.93").
The driest months (with the least rainfall) are January, September and November (0.87").
Average rainfall days in December
Chatham, PA
- Average rainfall days in December: 8.5 days
The month with the highest number of rainy days is July (14.9 days).
The month with the least rainy days is January (5.9 days).
Average snowfall in December
Chatham, PA
- Average snowfall in December: 0.59"
The month with the highest snowfall is March (1.26").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in December
Chatham, PA
- Average snowfall days in December: 2.1 days
The month with the highest number of snowfall days is January (5.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Chatham, 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 0min
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 48min).
Average sunshine days in December
Chatham, PA
- Average sunshine days in December: 19.9 days
The month with the most sunshine days is November (21.5 days).
The month with the least sunshine days is July (12.9 days).
Average UV index in December
Chatham, 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
Chatham, PA
- Average cloud cover in December: 46
The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).
Average visibility in December
Chatham, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).
