December weather forecast
Bryn Athyn, PA

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Weather in December

The first month of the winter, December, is still a chilly month in Bryn Athyn, Pennsylvania, with an average temperature fluctuating between 32.5°F (0.3°C) and 43.7°F (6.5°C).

Temperature

A shift in the average high-temperature occurs in December, reducing from a cool 52.7°F (11.5°C) in November to a frosty 43.7°F (6.5°C). Throughout December, an average low-temperature of 32.5°F (0.3°C) is expected.

Humidity

The average relative humidity in December is 76%.

Rainfall

In Bryn Athyn, in December, during 9.8 rainfall days, 3.03" (77mm) of precipitation is typically accumulated. Throughout the year, there are 153.8 rainfall days, and 30.94" (786mm) of precipitation is accumulated.

Snowfall

January through May, November and December are months with snowfall. In Bryn Athyn, in December, snow falls for 2.7 days, with typically accumulated 1.18" (30mm) of snow. In Bryn Athyn, during the entire year, snow falls for 16.8 days and aggregates up to 8.5" (216mm) of snow.

Daylight

With an average of 9h and 24min of daylight, December has the shortest days of the year in Bryn Athyn.
On the first day of the month, sunrise is at 7:03 am and sunset at 4:35 pm. On the last day of December, sunrise is at 7:22 am and sunset at 4:44 pm EST.

Sunshine

In December, the average sunshine is 5h.

UV index

The months with the lowest UV index are January through March, November and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: The average daily UV index of 2 in December transforms into the following instructions:
While extended sun exposure does not significantly affect most people, those with sensitive skin, children, and infants should always be protected. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Take into account! The reflection from snow can nearly double the Sun's UV radiation intensity.

Frequently asked questions

How cold does it get in Bryn Athyn in December?

In December, the average high-temperature and low-temperature are 43.7°F (6.5°C) and 32.5°F (0.3°C) respectively. The average heat index (a.k.a. 'feels like', 'apparent temperature'), which calculates the temperature value influenced by the moisture in the air, in August is computed to be 91.4°F (33°C).

What is the average humidity in December?

In Bryn Athyn, the average relative humidity in December is 76%.

How many days does it rain in December in Bryn Athyn?

In Bryn Athyn, in December, it is raining for 9.8 days, with typically 3.03" (77mm) of accumulated precipitation.

How much does it snow in December?

In December, it is snowing for 2.7 days. Throughout December, 1.18" (30mm) of snow is accumulated.

What is the month with the shortest days?

With an average of 9h and 24min of daylight, December has the shortest days of the year in Bryn Athyn.

What is the average length of the day in December?

In Bryn Athyn, the average day length in December is 9h and 22min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:03 am and sunset at 4:35 pm. On the last day of the month, sunrise is at 7:22 am and sunset at 4:44 pm EST.

How many hours of sunshine does Bryn Athyn have in December?

In December, the average sunshine duration is 5h.

When is the lowest UV index?

January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Bryn Athyn.

What is the UV index reading in December?

In Bryn Athyn, Pennsylvania, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a low health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in December
Bryn Athyn, PA

Average temperature in December - Bryn Athyn, PA
  • Average high temperature in December: 43.7°F

The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in December: 32.5°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 (25.2°F).

Average pressure in December
Bryn Athyn, PA

Average pressure in December - Bryn Athyn, 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 (29.93"Hg).

Average wind speed in December
Bryn Athyn, PA

Average wind speed in December - Bryn Athyn, PA
  • Average wind speed in December: 7.7mph

The windiest months (with the highest average wind speed) are March and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).

Average humidity in December
Bryn Athyn, PA

Average humidity in December - Bryn Athyn, PA
  • Average humidity in December: 76%

The months with the highest relative humidity are February and October (77%).
The months with the lowest relative humidity are April, July and August (71%).

Average rainfall in December
Bryn Athyn, PA

Average rainfall in December - Bryn Athyn, PA
  • Average rainfall in December: 3.03"

The wettest month (with the highest rainfall) is July (3.39").
The driest month (with the least rainfall) is January (1.89").

Average rainfall days in December
Bryn Athyn, PA

Average rainfall days in December - Bryn Athyn, PA
  • Average rainfall days in December: 9.8 days

The month with the highest number of rainy days is July (18.5 days).
The month with the least rainy days is November (7.5 days).

Average snowfall in December
Bryn Athyn, PA

Average snowfall in December - Bryn Athyn, PA
  • Average snowfall in December: 1.18"

The month with the highest snowfall is March (2.76").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Bryn Athyn, PA

Average snowfall days in December - Bryn Athyn, PA
  • Average snowfall days in December: 2.7 days

The month with the highest number of snowfall days is January (5.2 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in December /
Average sunshine in December
Bryn Athyn, PA

Average daylight in December / Average sunshine in December - Bryn Athyn, 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: 5h and 0min

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 42min).

Average sunshine days in December
Bryn Athyn, PA

Average sunshine days in December - Bryn Athyn, PA
  • Average sunshine days in December: 19 days

The month with the most sunshine days is November (21.2 days).
The month with the least sunshine days is July (10.4 days).

Average UV index in December
Bryn Athyn, PA

Average UV index in December - Bryn Athyn, 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, March, November and December (UV index 2).

Average cloud cover in December
Bryn Athyn, PA

Average cloud cover in December - Bryn Athyn, PA
  • Average cloud cover in December: 47

The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 33).

Average visibility in December
Bryn Athyn, PA

Average visibility in December - Bryn Athyn, PA
  • Average visibility in December: 6mi

The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).

Bryn Athyn, Pennsylvania, USA

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