December weather forecast
West Decatur, PA

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Weather in December

The first month of the winter, December, is also a wintry month in West Decatur, Pennsylvania, with an average temperature fluctuating between 36.3°F (2.4°C) and 25.9°F (-3.4°C).

Temperature

December indicates a shift in the average high-temperature, from November's chilly 45.9°F (7.7°C) to a cold 36.3°F (2.4°C). West Decatur's average low-temperature for the month of December records at a subzero cold 25.9°F (-3.4°C).

Humidity

In West Decatur, the average relative humidity in December is 84%.

Rainfall

In West Decatur, in December, it is raining for 11.4 days, with typically 1.57" (40mm) of accumulated precipitation. Throughout the year, in West Decatur, there are 159 rainfall days, and 23.46" (596mm) of precipitation is accumulated.

Snowfall

Months with snowfall in West Decatur are January through May, October through December. In West Decatur, in December, during 13.8 snowfall days, 4.13" (105mm) of snow is typically accumulated. Throughout the year, there are 67.7 snowfall days, and 23.54" (598mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December, sunrise is at 7:19 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 4:55 pm EST.

Sunshine

In December, the average sunshine is 3.5h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index reading of 2, and below, represents a low threat to health from unprotected exposure to Sun's UV rays for the ordinary person.
Note: In December, an average UV index of 1 transforms into the following instructions:
Sun exposure does not present considerable issues for many, yet infants, fair-skinned people, and children necessitate constant protection. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Stay alert! Snow's reflective properties can almost double the UV radiation from the Sun.
Updated: Jul 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

The average high-temperature and low-temperature during December are 36.3°F (2.4°C) and 25.9°F (-3.4°C) respectively. In July, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which takes the relative humidity and factors it into the air temperature reading, is evaluated at 86°F (30°C).

What is the average humidity in December?

The average relative humidity in December is 84%.

How much does it rain in December?

In West Decatur, in December, during 11.4 rainfall days, 1.57" (40mm) of precipitation is typically accumulated.

How much does it snow in December?

In West Decatur, during December, snow falls for 13.8 days and regularly aggregates up to 4.13" (105mm) of snow.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 18min of daylight.

How many hours of daylight does West Decatur have in December?

In West Decatur, the average day length in December is 9h and 17min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:19 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:37 am and sunset at 4:55 pm EST.

How many hours of sunshine does West Decatur have in December?

The average sunshine duration in December is 3.5h.

When is the lowest UV index?

December is the month with the lowest UV index, with an average maximum UV index of 1.

How high is the UV index in December?

In West Decatur, Pennsylvania, the average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a minimal health vulnerability from 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
West Decatur, PA

Average temperature in December - West Decatur, PA
  • Average high temperature in December: 36.3°F

The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (30.6°F).

  • Average low temperature in December: 25.9°F

The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is January (18°F).

Average pressure in December
West Decatur, PA

Average pressure in December - West Decatur, PA
  • Average pressure in December: 30.1"Hg

The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in December
West Decatur, PA

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

The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest month (with the lowest average wind speed) is August (5mph).

Average humidity in December
West Decatur, PA

Average humidity in December - West Decatur, PA
  • Average humidity in December: 84%

The month with the highest relative humidity is February (85%).
The month with the lowest relative humidity is July (76%).

Average rainfall in December
West Decatur, PA

Average rainfall in December - West Decatur, PA
  • Average rainfall in December: 1.57"

The wettest month (with the highest rainfall) is May (2.87").
The driest month (with the least rainfall) is November (1.42").

Average rainfall days in December
West Decatur, PA

Average rainfall days in December - West Decatur, PA
  • Average rainfall days in December: 11.4 days

The month with the highest number of rainy days is May (17.9 days).
The month with the least rainy days is January (8.1 days).

Average snowfall in December
West Decatur, PA

Average snowfall in December - West Decatur, PA
  • Average snowfall in December: 4.13"

The month with the highest snowfall is January (6.02").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
West Decatur, PA

Average snowfall days in December - West Decatur, PA
  • Average snowfall days in December: 13.8 days

The month with the highest number of snowfall days is January (18.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
West Decatur, PA

Average daylight in December / Average sunshine in December - West Decatur, PA
  • Average daylight in December: 9h and 2min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in December: 3h and 3min

The months with the most sunshine are July and August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).

Average sunshine days in December
West Decatur, PA

Average sunshine days in December - West Decatur, PA
  • Average sunshine days in December: 10.5 days

The month with the most sunshine days is September (15.4 days).
The month with the least sunshine days is February (8.7 days).

Average UV index in December
West Decatur, PA

Average UV index in December - West Decatur, PA
  • Average UV index in December: 1

The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
West Decatur, PA

Average cloud cover in December - West Decatur, PA
  • Average cloud cover in December: 64

The month with the most cloud cover is January (Cloud cover 67).
The months with the least cloud cover are July and August (Cloud cover 38).

Average visibility in December
West Decatur, PA

Average visibility in December - West Decatur, PA
  • Average visibility in December: 5mi

The months with the highest visibility are January, March, April, May, June, July, August, October, November and December (5mi).
The months with the lowest visibility are February and September (4mi).

West Decatur, Pennsylvania, USA

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