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
The onset of December comes with a shift in the average high-temperature, falling from a fresh 50.5°F (10.3°C) in November to a wintry 41.2°F (5.1°C). The nights of December anticipate an average low-temperature of 28.9°F (-1.7°C).Humidity
February, May, October and December, with an average relative humidity of 79%, are the most humid months in Greencastle.Rainfall
In Greencastle, during December, the rain falls for 10.3 days and regularly aggregates up to 2.01" (51mm) of precipitation. In Greencastle, during the entire year, the rain falls for 161.8 days and collects up to 28.07" (713mm) of precipitation.Snowfall
Months with snowfall are January through April, October through December. In Greencastle, Pennsylvania, in December, snow falls for 4.7 days, with typically accumulated 2.13" (54mm) of snow. In Greencastle, during the entire year, snow falls for 26.6 days and aggregates up to 14.69" (373mm) of snow.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:13 am and sunset at 4:46 pm. On the last day of December, sunrise is at 7:31 am and sunset at 4:56 pm EST.
Sunshine
In December, the average sunshine in Greencastle is 4.8h.UV index
The months with the lowest UV index in Greencastle are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The daily high UV index of 2 in December translates into this advice:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Frequently asked questions
Is it cold in Greencastle during December?
What are the most humid months in Greencastle?
What is the average humidity in December in Greencastle?
How many days does it rain in December in Greencastle?
How many days does it snow in December in Greencastle?
What is the month with the shortest days in Greencastle?
How many hours of daylight does Greencastle have in December?
When is the sunrise / sunset in December in Greencastle?
How many hours of sunshine does Greencastle have in December?
What are the months with the lowest UV index in Greencastle?
What is the UV index intensity in December in Greencastle?
Average temperature in December
Greencastle, PA
- Average high temperature in December: 41.2°F
The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in December: 28.9°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (22.5°F).
Average pressure in December
Greencastle, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Greencastle, PA
- Average wind speed in December: 7mph
The windiest month (with the highest average wind speed) is January (7.7mph).
The calmest months (with the lowest average wind speed) are July and August (4.5mph).
Average humidity in December
Greencastle, PA
- Average humidity in December: 79%
The months with the highest relative humidity are February, May, October and December (79%).
The months with the lowest relative humidity are April and July (75%).
Average rainfall in December
Greencastle, PA
- Average rainfall in December: 2.01"
The wettest month (with the highest rainfall) is May (3.15").
The driest month (with the least rainfall) is January (1.85").
Average rainfall days in December
Greencastle, PA
- Average rainfall days in December: 10.3 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is November (9 days).
Average snowfall in December
Greencastle, PA
- Average snowfall in December: 2.13"
The month with the highest snowfall is January (4.53").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Greencastle, PA
- Average snowfall days in December: 4.7 days
The month with the highest number of snowfall days is January (8.1 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Greencastle, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 5min
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 36min).
Average sunshine days in December
Greencastle, PA
- Average sunshine days in December: 17.1 days
The month with the most sunshine days is November (18.5 days).
The month with the least sunshine days is May (10.4 days).
Average UV index in December
Greencastle, 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, November and December (UV index 2).
Average cloud cover in December
Greencastle, PA
- Average cloud cover in December: 50
The months with the most cloud cover are January, February and December (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Greencastle, PA
- Average visibility in December: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).
Greencastle, Pennsylvania, USA
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