December weather forecast
National Hill, PA

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Weather in December

December, the first month of the winter in National Hill, is also a wintry month, with an average temperature fluctuating between 28.4°F (-2°C) and 39.7°F (4.3°C).

Temperature

During the transition into December, National Hill observes a decrease in the average high-temperature, falling from a frosty 49.3°F (9.6°C) in November to an icy 39.7°F (4.3°C). In December, National Hill encounters an average low-temperature of 28.4°F (-2°C) during the night.

Humidity

The average relative humidity in December is 83%.

Rainfall

In National Hill, in December, during 8.2 rainfall days, 0.87" (22mm) of precipitation is typically accumulated. In National Hill, Pennsylvania, during the entire year, the rain falls for 132.6 days and collects up to 11.5" (292mm) of precipitation.

Snowfall

Months with snowfall are January through April, November and December. In National Hill, in December, snow falls for 6.4 days, with typically accumulated 0.59" (15mm) of snow. In National Hill, during the entire year, snow falls for 32.5 days and aggregates up to 3.66" (93mm) of snow.

Daylight

December has the shortest days of the year, with an average of 9h and 24min of daylight.
On the first day of the month, sunrise is at 7:24 am and sunset at 4:54 pm. On the last day of December, sunrise is at 7:43 am and sunset at 5:04 pm EST.

Sunshine

The average sunshine in December is 3.4h.

UV index

December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for average individuals.
Note: The maximum UV index of 1 during December leads to these instructions:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. 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. Note well! The intensity of the Sun's UV rays can be nearly doubled by snow reflection.
Updated: Jul 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

National Hill in December has an average high-temperature of 39.7°F (4.3°C) and an average low-temperature of 28.4°F (-2°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines air temperature and relative humidity, in August is calculated to be 87.8°F (31°C).

What is the average humidity in December?

In December, the average relative humidity in National Hill is 83%.

How many days does it rain in December?

In December, the rain falls for 8.2 days. Throughout December, 0.87" (22mm) of precipitation is accumulated.

How many days does it snow in December?

In December, in National Hill, it is snowing for 6.4 days. Throughout December, 0.59" (15mm) 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.

What is the average length of the day in December?

In December, the average day length is 9h and 21min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:24 am and sunset at 4:54 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 5:04 pm EST.

How many hours of sunshine does National Hill have in December?

In National Hill, the average sunshine duration in December is 3.4h.

When is the lowest UV index in National Hill?

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 National Hill, the average daily maximum UV index in December is 1. A UV Index 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
National Hill, PA

Average temperature in December - National Hill, PA
  • Average high temperature in December: 39.7°F

The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in December: 28.4°F

The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (21°F).

Average pressure in December
National Hill, PA

Average pressure in December - National Hill, PA
  • Average pressure in December: 30.11"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
National Hill, PA

Average wind speed in December - National Hill, PA
  • Average wind speed in December: 7.3mph

The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).

Average humidity in December
National Hill, PA

Average humidity in December - National Hill, PA
  • Average humidity in December: 83%

The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are July and August (75%).

Average rainfall in December
National Hill, PA

Average rainfall in December - National Hill, PA
  • Average rainfall in December: 0.87"

The wettest month (with the highest rainfall) is July (1.34").
The driest month (with the least rainfall) is November (0.67").

Average rainfall days in December
National Hill, PA

Average rainfall days in December - National Hill, PA
  • Average rainfall days in December: 8.2 days

The month with the highest number of rainy days is July (15.6 days).
The month with the least rainy days is February (6.4 days).

Average snowfall in December
National Hill, PA

Average snowfall in December - National Hill, PA
  • Average snowfall in December: 0.59"

The month with the highest snowfall is February (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
National Hill, PA

Average snowfall days in December - National Hill, PA
  • Average snowfall days in December: 6.4 days

The month with the highest number of snowfall days is January (9.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in December /
Average sunshine in December
National Hill, PA

Average daylight in December / Average sunshine in December - National Hill, 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: 3h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days in December
National Hill, PA

Average sunshine days in December - National Hill, PA
  • Average sunshine days in December: 18.5 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12.2 days).

Average UV index in December
National Hill, PA

Average UV index in December - National Hill, PA
  • Average UV index in December: 1

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
National Hill, PA

Average cloud cover in December - National Hill, PA
  • Average cloud cover in December: 64

The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).

Average visibility in December
National Hill, PA

Average visibility in December - National Hill, PA
  • Average visibility in December: 5mi

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

National Hill, Pennsylvania, USA

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