December weather forecast
Harleysville, PA

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Weather in December

December, the first month of the winter in Harleysville, is also a wintry month, with an average temperature varying between 41.5°F (5.3°C) and 30.4°F (-0.9°C).

Temperature

December implies a gentle temperature shift, with average high-temperatures reducing from November's cool 50.9°F (10.5°C) to an icy 41.5°F (5.3°C). Harleysville, in the month of December, anticipates a consistent average low-temperature of 30.4°F (-0.9°C).

Humidity

In Harleysville, the average relative humidity in December is 80%.

Rainfall

In Harleysville, during December, the rain falls for 8 days and regularly aggregates up to 1.34" (34mm) of precipitation. In Harleysville, during the entire year, the rain falls for 128.6 days and collects up to 15.16" (385mm) of precipitation.

Snowfall

Months with snowfall are January through May, November and December. In Harleysville, Pennsylvania, in December, snow falls for 2 days, with typically accumulated 1.34" (34mm) of snow. In Harleysville, during the entire year, snow falls for 17 days and aggregates up to 5.43" (138mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 24min of daylight.
On the first day of the month, sunrise is at 7:05 am and sunset at 4:36 pm. On the last day of December, sunrise is at 7:24 am and sunset at 4:45 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. A UV Index estimate of 2, and below, represents a low health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: An average UV index of 2 in December transforms into this advice:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. The Sun's radiation is especially intense around midday; try to stay in shade during this period. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
Updated: Jul 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

Harleysville in December has an average high-temperature of 41.5°F (5.3°C) and an average low-temperature of 30.4°F (-0.9°C). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines air temperature and relative humidity, is appraised at 87.8°F (31°C).

What is the average humidity in December?

The average relative humidity in December is 80%.

How much does it rain in December?

In December, the rain falls for 8 days. Throughout December, 1.34" (34mm) of precipitation is accumulated.

How much does it snow in December?

In Harleysville, in December, snow falls for 2 days, with typically accumulated 1.34" (34mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 24min of daylight.

How many hours of daylight does Harleysville have in December?

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

When are sunrise and sunset in December?

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 7:24 am and sunset at 4:45 pm EST.

How many hours of sunshine does Harleysville have in December?

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

What is the month with 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.

How high is the UV index in December?

In December, the average daily maximum UV index in Harleysville is 2. A UV Index estimate of 2, and below, represents a minimal hazard to health 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
Harleysville, PA

Average temperature in December - Harleysville, PA
  • Average high temperature in December: 41.5°F

The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (35.2°F).

  • Average low temperature in December: 30.4°F

The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).

Average pressure in December
Harleysville, PA

Average pressure in December - Harleysville, 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
Harleysville, PA

Average wind speed in December - Harleysville, PA
  • Average wind speed in December: 7.5mph

The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5mph).

Average humidity in December
Harleysville, PA

Average humidity in December - Harleysville, PA
  • Average humidity in December: 80%

The month with the highest relative humidity is February (81%).
The months with the lowest relative humidity are April and July (75%).

Average rainfall in December
Harleysville, PA

Average rainfall in December - Harleysville, PA
  • Average rainfall in December: 1.34"

The wettest month (with the highest rainfall) is July (1.97").
The driest month (with the least rainfall) is January (0.87").

Average rainfall days in December
Harleysville, PA

Average rainfall days in December - Harleysville, PA
  • Average rainfall days in December: 8 days

The month with the highest number of rainy days is July (15.7 days).
The month with the least rainy days is January (5.7 days).

Average snowfall in December
Harleysville, PA

Average snowfall in December - Harleysville, PA
  • Average snowfall in December: 1.34"

The month with the highest snowfall is March (1.46").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in December
Harleysville, PA

Average snowfall days in December - Harleysville, PA
  • Average snowfall days in December: 2 days

The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Harleysville, 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 36min).

Average sunshine days in December
Harleysville, PA

Average sunshine days in December - Harleysville, PA
  • Average sunshine days in December: 20.1 days

The month with the most sunshine days is November (21.4 days).
The month with the least sunshine days is July (12.8 days).

Average UV index in December
Harleysville, PA

Average UV index in December - Harleysville, 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
Harleysville, PA

Average cloud cover in December - Harleysville, 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 32).

Average visibility in December
Harleysville, PA

Average visibility in December - Harleysville, 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).

Harleysville, Pennsylvania, USA

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