December weather forecast
Exton, PA

Weather in December

December, the first month of the winter in Exton, is still a cold month, with an average temperature fluctuating between 42.3°F (5.7°C) and 31.1°F (-0.5°C).

Temperature

In December, the average high-temperature decreases from a cool 51.4°F (10.8°C) in November to a wintry 42.3°F (5.7°C). The average low-temperature, is 31.1°F (-0.5°C).

Humidity

In Exton, the average relative humidity in December is 78%.

Rainfall

In Exton, it is raining for 7.7 days, with typically 1.14" (29mm) of accumulated precipitation. In Exton, during the entire year, the rain falls for 124.6 days and collects up to 14.25" (362mm) of precipitation.

Snowfall

Months with snowfall are January through May, November and December. In Exton, snow falls for 2.2 days, with typically accumulated 0.79" (20mm) of snow. Throughout the year, there are 18.5 snowfall days, and 5.51" (140mm) of snow is accumulated.

Daylight

The month with the shortest days is December, with an average of 9h and 23min of daylight.
On the first day of December in Exton, Pennsylvania, sunrise is at 7:05 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:24 am and sunset at 4:46 pm EST.

Sunshine

The average sunshine in December 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 Exton. A UV Index of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the average person.
Note: The daily maximum UV index of 2 in December interpret into the following advice:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Caution! The reflection of snow can nearly double the intensity of the Sun's UV radiation.
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FAQ

What is the temperature in December in Exton?

In December, in Exton, the average high-temperature is 42.3°F (5.7°C), and the average low-temperature is 31.1°F (-0.5°C). The average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), which combines air temperature and relative humidity, in August is appraised at 87.8°F (31°C).

What is the average humidity in December in Exton?

In Exton, the average relative humidity in December is 78%.

How many days does it rain in December in Exton?

In Exton, Pennsylvania, in December, it is raining for 7.7 days, with typically 1.14" (29mm) of accumulated precipitation.

How much does it snow in Exton in December?

In Exton, Pennsylvania, in December, snow falls for 2.2 days, with typically accumulated 0.79" (20mm) of snow.

What is the month with the shortest days in Exton?

December has the shortest days of the year, with an average of 9h and 23min of daylight.

What is the average length of the day in December in Exton?

In Exton, Pennsylvania, the average day length in December is 9h and 23min.

What time are sunrise and sunset in December in Exton?

In December, on the first day of the month, sunrise is at 7:05 am and sunset at 4:37 pm. On the last day of the month, in Exton, sunrise is at 7:24 am and sunset at 4:46 pm EST.

How long on average sun shines in December in Exton?

In December, the average sunshine duration in Exton is 4.8h.

What are the months with the lowest UV index in Exton?

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

What is the UV index reading in December in Exton?

In December, the average daily maximum UV index in Exton, Pennsylvania, is 2. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV radiation.
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
Exton, PA

Average temperature in December - Exton, PA
  • Average high temperature in December: 42.3°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (36.1°F).

  • Average low temperature in December: 31.1°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).

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Average pressure in December
Exton, PA

Average pressure in December - Exton, PA
  • Average pressure in December: 30.1"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).

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Average wind speed in December
Exton, PA

Average wind speed in December - Exton, PA
  • Average wind speed in December: 7.9mph

The windiest month (with the highest average wind speed) is March (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

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Average humidity in December
Exton, PA

Average humidity in December - Exton, 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 and July (73%).

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Average rainfall in December
Exton, PA

Average rainfall in December - Exton, PA
  • Average rainfall in December: 1.14"

The wettest month (with the highest rainfall) is August (1.89").
The driest month (with the least rainfall) is January (0.79").

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Average rainfall days in December
Exton, PA

Average rainfall days in December - Exton, PA
  • Average rainfall days in December: 7.7 days

The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is January (5 days).

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Average snowfall in December
Exton, PA

Average snowfall in December - Exton, PA
  • Average snowfall in December: 0.79"

The month with the highest snowfall is March (1.57").
The months with the least snowfall are June, July, August, September and October (0").

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Average snowfall days in December
Exton, PA

Average snowfall days in December - Exton, PA
  • Average snowfall days in December: 2.2 days

The month with the highest number of snowfall days is January (5.4 days).
The months with the least snowfall days are June, July, August and September (0 days).

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Average daylight in December /
Average sunshine in December
Exton, PA

Average daylight in December / Average sunshine in December - Exton, PA
  • Average daylight in December: 9h and 23min

The month with the longest days is June (Average daylight: 14h and 58min).
The month with the shortest days is December (Average daylight: 9h and 23min).

  • Average sunshine in December: 4h and 48min

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).

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Average sunshine days in December
Exton, PA

Average sunshine days in December - Exton, PA
  • Average sunshine days in December: 20.5 days

The month with the most sunshine days is November (21.7 days).
The month with the least sunshine days is June (13.3 days).

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Average UV index in December
Exton, PA

Average UV index in December - Exton, 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).

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Average cloud cover in December
Exton, PA

Average cloud cover in December - Exton, 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).

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Average visibility in December
Exton, PA

Average visibility in December - Exton, 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).

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