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
Cornwall's weather changes with the onset of December, slightly falling from a frosty 49.5°F (9.7°C) in November to a cold 40.3°F (4.6°C). The temperature in Cornwall lowers to an average of 29.3°F (-1.5°C) during December nights.Humidity
In Cornwall, the average relative humidity in December is 80%.Rainfall
In Cornwall, in December, during 9.2 rainfall days, 1.1" (28mm) of precipitation is typically accumulated. Throughout the year, in Cornwall, there are 137.4 rainfall days, and 16.26" (413mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In December, it is snowing for 3.3 days. Throughout December, 0.98" (25mm) of snow is accumulated. Throughout the year, there are 19.5 snowfall days, and 6.69" (170mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:09 am and sunset at 4:40 pm. On the last day of December, sunrise is at 7:28 am and sunset at 4:49 pm EST.
Sunshine
The average sunshine in December is 4.6h.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 estimate of 2, and below, represents a minimal health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 2 during December translates into these guidelines:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Remember to consider! The UV radiation from the Sun can be intensified nearly twice by the reflection of snow.
Frequently asked questions
Is it cold in Cornwall during December?
What is the average humidity in December in Cornwall?
How many days does it rain in December in Cornwall?
How much does it snow in Cornwall in December?
What is the month with the shortest days in Cornwall?
What is the average length of the day in December in Cornwall?
When is the sunrise / sunset in December in Cornwall?
How long on average sun shines in December in Cornwall?
What is the month with the lowest UV index in Cornwall?
What is the UV index reading in December in Cornwall?
Average temperature in December
Cornwall, PA
- Average high temperature in December: 40.3°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (33.8°F).
- Average low temperature in December: 29.3°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (21.6°F).
Average pressure in December
Cornwall, 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
Cornwall, PA
- Average wind speed in December: 8mph
The windiest month (with the highest average wind speed) is March (8.8mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in December
Cornwall, PA
- Average humidity in December: 80%
The months with the highest relative humidity are February, May and October (81%).
The month with the lowest relative humidity is April (76%).
Average rainfall in December
Cornwall, PA
- Average rainfall in December: 1.1"
The wettest month (with the highest rainfall) is August (2.13").
The driest month (with the least rainfall) is February (0.94").
Average rainfall days in December
Cornwall, PA
- Average rainfall days in December: 9.2 days
The month with the highest number of rainy days is May (15.9 days).
The month with the least rainy days is January (6.7 days).
Average snowfall in December
Cornwall, PA
- Average snowfall in December: 0.98"
The month with the highest snowfall is January (1.97").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Cornwall, PA
- Average snowfall days in December: 3.3 days
The month with the highest number of snowfall days is January (5.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Cornwall, 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 24min).
- 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
Cornwall, PA
- Average sunshine days in December: 18.7 days
The month with the most sunshine days is January (20.3 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in December
Cornwall, 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
Cornwall, PA
- Average cloud cover in December: 51
The months with the most cloud cover are February and December (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Cornwall, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, November and December (6mi).
The months with the lowest visibility are May, August, September and October (5mi).
Cornwall, Pennsylvania, USA
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