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
A subtle change in temperatures is noted as November gives way to December, with average highs reducing from a cool 52°F (11.1°C) to a frosty 43.2°F (6.2°C). Bryn Mawr records an average low of 32°F (0°C) throughout the nights in December.Humidity
In Bryn Mawr, the average relative humidity in December is 77%.Rainfall
In Bryn Mawr, Pennsylvania, in December, it is raining for 6.5 days, with typically 0.91" (23mm) of accumulated precipitation. In Bryn Mawr, Pennsylvania, during the entire year, the rain falls for 111.8 days and collects up to 9.69" (246mm) of precipitation.Snowfall
Months with snowfall in Bryn Mawr are January through March, November and December. In Bryn Mawr, in December, during 2.1 snowfall days, 0.63" (16mm) of snow is typically accumulated. Throughout the year, in Bryn Mawr, there are 15.1 snowfall days, and 3.66" (93mm) of snow is accumulated.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year in Bryn Mawr, Pennsylvania.On the first day of December, sunrise is at 7:04 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:23 am and sunset at 4:46 pm EST.
Sunshine
In December, the average sunshine is 4.9h.UV index
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation for the ordinary person.Note: In December, a regular UV index of 2 translates into these guidelines:
While most people are not greatly affected by extended sun exposure, those with fair skin, babies, and children must always have protection. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Frequently asked questions
Is December cold in Bryn Mawr?
What is the average humidity in December in Bryn Mawr?
How much does it rain in Bryn Mawr in December?
How many days does it snow in December in Bryn Mawr?
What is the month with the shortest days in Bryn Mawr?
What is the average length of the day in December in Bryn Mawr?
When are sunrise and sunset in December in Bryn Mawr?
How many hours of sunshine does Bryn Mawr have in December?
When is the lowest UV index in Bryn Mawr?
How high is the UV index in December in Bryn Mawr?
Average temperature in December
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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 5min
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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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
Bryn Mawr, 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).
Bryn Mawr, Pennsylvania, USA
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