December weather forecastRosemont, PA
December
Weather in December
The first month of the winter, December, is still a chilly month in Rosemont, Pennsylvania, with an average temperature varying between 43.2°F (6.2°C) and 32°F (0°C).Temperature
December ushers in a minute temperature change, with average high-temperatures reducing from November's cool 52°F (11.1°C) to a chilly 43.2°F (6.2°C). Rosemont, during December, witnesses an average low-temperature of 32°F (0°C).Humidity
In December, the average relative humidity is 77%.Rainfall
In December, the rain falls for 6.5 days. Throughout December, 0.91" (23mm) of precipitation is accumulated. Throughout the year, there are 111.8 rainfall days, and 9.69" (246mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through March, November and December. In Rosemont, during December, snow falls for 2.1 days and regularly aggregates up to 0.63" (16mm) of snow. In Rosemont, during the entire year, snow falls for 15.1 days and aggregates up to 3.66" (93mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:04 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:23 am and sunset at 4:46 pm EST.
Sunshine
The average sunshine in December is 4.9h.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 low health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum UV index of 2 during December translates into these guidelines:
Babies, children, and individuals with sensitive skin should always have protection against extended sun exposure. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation. Guard yourself! Snow reflection can almost double the UV radiation from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Rosemont, PA
- Average high temperature in December: 43.2°F
The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is January (36.7°F).
- Average low temperature in December: 32°F
The month with the highest average low temperature is July (68.9°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in December
Rosemont, PA
- Average pressure in December: 30.09"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Rosemont, PA
- Average wind speed in December: 7.8mph
The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).
Average humidity in December
Rosemont, PA
- Average humidity in December: 77%
The months with the highest relative humidity are February and October (78%).
The months with the lowest relative humidity are April, July and August (71%).
Average rainfall in December
Rosemont, PA
- Average rainfall in December: 0.91"
The wettest months (with the highest rainfall) are July and August (1.14").
The driest month (with the least rainfall) is January (0.55").
Average rainfall days in December
Rosemont, PA
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is July (13.3 days).
The month with the least rainy days is January (5.3 days).
Average snowfall in December
Rosemont, PA
- Average snowfall in December: 0.63"
The months with the highest snowfall are February and March (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Rosemont, PA
- Average snowfall days in December: 2.1 days
The month with the highest number of snowfall days is January (4.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Rosemont, 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: 4h and 54min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in December
Rosemont, PA
- Average sunshine days in December: 22.2 days
The month with the most sunshine days is November (22.5 days).
The month with the least sunshine days is July (14.9 days).
Average UV index in December
Rosemont, 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
Rosemont, PA
- Average cloud cover in December: 48
The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Rosemont, 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).
