December weather forecastArnold, PA
December
Weather in December
The first month of the winter, December, is also a wintry month in Arnold, Pennsylvania, with an average temperature varying between 38.7°F (3.7°C) and 27.5°F (-2.5°C).Temperature
The average high-temperature drops in December, from November's frosty 48.4°F (9.1°C) to an icy 38.7°F (3.7°C). Arnold experiences a steady low-temperature of 27.5°F (-2.5°C) throughout December.Humidity
In Arnold, the average relative humidity in December is 84%.Rainfall
In Arnold, in December, it is raining for 13.7 days, with typically 2.99" (76mm) of accumulated precipitation. Throughout the year, there are 185.5 rainfall days, and 35.59" (904mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Arnold, during December, snow falls for 13.5 days and regularly aggregates up to 4.72" (120mm) of snow. Throughout the year, there are 63.1 snowfall days, and 25.12" (638mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 18min of daylight.On the first day of December in Arnold, sunrise is at 7:23 am and sunset at 4:52 pm. On the last day of the month, sunrise is at 7:42 am and sunset at 5:02 pm EST.
Sunshine
In December, the average sunshine is 3.1h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for the ordinary person.Note: An average maximum UV index of 1 in December leads to these recommendations:
Although prolonged sun exposure does not typically bother most people, children, babies, and those with sensitive skin should always have protection. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Arnold, PA
- Average high temperature in December: 38.7°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (32.7°F).
- Average low temperature in December: 27.5°F
The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).
Average pressure in December
Arnold, PA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in December
Arnold, PA
- Average wind speed in December: 7.5mph
The windiest month (with the highest average wind speed) is January (8.1mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in December
Arnold, PA
- Average humidity in December: 84%
The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are April, July and August (76%).
Average rainfall in December
Arnold, PA
- Average rainfall in December: 2.99"
The wettest months (with the highest rainfall) are April and May (3.66").
The driest month (with the least rainfall) is November (2.2").
Average rainfall days in December
Arnold, PA
- Average rainfall days in December: 13.7 days
The month with the highest number of rainy days is May (20.2 days).
The month with the least rainy days is January (11.1 days).
Average snowfall in December
Arnold, PA
- Average snowfall in December: 4.72"
The month with the highest snowfall is January (6.73").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Arnold, PA
- Average snowfall days in December: 13.5 days
The month with the highest number of snowfall days is January (18 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Arnold, PA
- Average daylight in December: 9h and 18min
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 18min).
- Average sunshine in December: 3h and 6min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).
Average sunshine days in December
Arnold, PA
- Average sunshine days in December: 9 days
The month with the most sunshine days is November (14.8 days).
The month with the least sunshine days is January (7.3 days).
Average UV index in December
Arnold, PA
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Arnold, PA
- Average cloud cover in December: 67
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in December
Arnold, PA
- Average visibility in December: 5mi
The months with the highest visibility are April and August (6mi).
The months with the lowest visibility are January and February (4mi).
