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 decrease in the average high-temperature marks December, falling from November's cool 51.8°F (11°C) to a cold 42.6°F (5.9°C). Berwyn, in the month of December, anticipates a consistent average low-temperature of 31.1°F (-0.5°C).Humidity
In December, the average relative humidity is 78%.Rainfall
In December, the rain falls for 9.1 days. Throughout December, 1.81" (46mm) of precipitation is accumulated. In Berwyn, during the entire year, the rain falls for 138.1 days and collects up to 20.79" (528mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Berwyn, in December, snow falls for 2.5 days, with typically accumulated 1.46" (37mm) of snow. In Berwyn, during the entire year, snow falls for 19.3 days and aggregates up to 7.68" (195mm) 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 December, sunrise is at 7:05 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 4.8h.UV index
January through March, November and December, with an average maximum UV index of 2, are months with the lowest UV index in Berwyn. A UV Index value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: A maximum high UV index of 2 in December translates into the following recommendations:
It is important to always shield children, babies, and individuals with sensitive skin from prolonged exposure to the sun. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Stay sun-safe with clothing that is both closely woven and worn loosely. Remember! The Sun's UV radiation can be magnified almost twofold by the reflection of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What is the average humidity in December?
How many days does it rain in December in Berwyn?
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?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Berwyn, PA
- Average high temperature in December: 42.6°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (36.5°F).
- Average low temperature in December: 31.1°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Berwyn, 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
Berwyn, PA
- Average wind speed in December: 7.8mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in December
Berwyn, PA
- Average humidity in December: 78%
The months with the highest relative humidity are February and October (79%).
The months with the lowest relative humidity are April, July and August (73%).
Average rainfall in December
Berwyn, PA
- Average rainfall in December: 1.81"
The wettest month (with the highest rainfall) is August (2.72").
The driest months (with the least rainfall) are January, February and November (1.3").
Average rainfall days in December
Berwyn, PA
- Average rainfall days in December: 9.1 days
The month with the highest number of rainy days is July (16.8 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in December
Berwyn, PA
- Average snowfall in December: 1.46"
The month with the highest snowfall is March (1.93").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Berwyn, PA
- Average snowfall days in December: 2.5 days
The month with the highest number of snowfall days is January (6.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Berwyn, 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 30min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in December
Berwyn, PA
- Average sunshine days in December: 19.2 days
The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is July (12.7 days).
Average UV index in December
Berwyn, 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
Berwyn, PA
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in December
Berwyn, 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).
Berwyn, Pennsylvania, USA
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