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
December's arrival correlates with a reduction in the average high-temperature, down from a chilly 48.4°F (9.1°C) in November to an icy 38.8°F (3.8°C). During December, the nighttime temperature averages to a subzero cold 27.5°F (-2.5°C).Humidity
In Shirleysburg, the average relative humidity in December is 81%.Rainfall
In Shirleysburg, during December, the rain falls for 10.9 days and regularly aggregates up to 2.36" (60mm) of precipitation. Throughout the year, there are 164.3 rainfall days, and 28.19" (716mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall. In December, in Shirleysburg, it is snowing for 7.7 days. Throughout December, 2.56" (65mm) of snow is accumulated. In Shirleysburg, during the entire year, snow falls for 40.6 days and aggregates up to 17.91" (455mm) 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 7:15 am and sunset at 4:45 pm. On the last day of December, sunrise is at 7:34 am and sunset at 4:55 pm EST.
Sunshine
In December, the average sunshine is 4.3h.UV index
January through March, October through December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for average individuals.Note: In December, the maximum UV index of 2 transforms into these recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.
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Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold does it get in December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How long on average sun shines in December in Shirleysburg?
When is the lowest UV index?
What is the UV index intensity in December in Shirleysburg?
Average temperature in December
Shirleysburg, PA
- Average high temperature in December: 38.8°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in December
Shirleysburg, 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
Shirleysburg, PA
- Average wind speed in December: 7.1mph
The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in December
Shirleysburg, PA
- Average humidity in December: 81%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is July (75%).
Average rainfall in December
Shirleysburg, PA
- Average rainfall in December: 2.36"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in December
Shirleysburg, PA
- Average rainfall days in December: 10.9 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (9.5 days).
Average snowfall in December
Shirleysburg, PA
- Average snowfall in December: 2.56"
The month with the highest snowfall is January (5.24").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Shirleysburg, PA
- Average snowfall days in December: 7.7 days
The month with the highest number of snowfall days is January (12.2 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
Shirleysburg, 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 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Shirleysburg, PA
- Average sunshine days in December: 14.2 days
The month with the most sunshine days is November (16.7 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in December
Shirleysburg, PA
- Average UV index in December: 2
The months with the highest UV index are May and June (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in December
Shirleysburg, PA
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July and August (Cloud cover 34).
Average visibility in December
Shirleysburg, PA
- Average visibility in December: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).
Shirleysburg, Pennsylvania, USA
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