December weather forecast
Heilwood, PA

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Weather in December

The first month of the winter, December, is still a cold month in Heilwood, Pennsylvania, with an average temperature varying between 26.4°F (-3.1°C) and 36.5°F (2.5°C).

Temperature

The average high-temperature decreases in December, shifting from a frosty 46.2°F (7.9°C) in November to an icy 36.5°F (2.5°C). Throughout December, Heilwood registers a consistent average low-temperature of 26.4°F (-3.1°C).

Humidity

In December, the average relative humidity is 85%.

Rainfall

In December, in Heilwood, the rain falls for 7.2 days. Throughout December, 0.94" (24mm) of precipitation is accumulated. Throughout the year, there are 121.6 rainfall days, and 10.75" (273mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, October through December. In December, in Heilwood, it is snowing for 9.2 days. Throughout December, 2.01" (51mm) of snow is accumulated. In Heilwood, during the entire year, snow falls for 49.1 days and aggregates up to 10.43" (265mm) of snow.

Daylight

The month with the shortest days in Heilwood is December, with an average of 9h and 18min of daylight.
On the first day of the month, sunrise is at 7:20 am and sunset at 4:49 pm. On the last day of December, sunrise is at 7:39 am and sunset at 4:58 pm EST.

Sunshine

The average sunshine in December is 3.3h.

UV index

With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 1 in December transforms into the following instructions:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Updated: Aug 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

December temperatures vary between a high-temperature of 36.5°F (2.5°C) and a low-temperature of 26.4°F (-3.1°C).

What is the average humidity in December?

The average relative humidity in December is 85%.

How many days does it rain in December?

In Heilwood, during December, the rain falls for 7.2 days and regularly aggregates up to 0.94" (24mm) of precipitation.

How many days does it snow in December?

In Heilwood, Pennsylvania, in December, snow falls for 9.2 days, with typically accumulated 2.01" (51mm) of snow.

What is the month with the shortest days?

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

How many hours of daylight does Heilwood have in December?

In Heilwood, the average day length in December is 9h and 19min.

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:20 am and sunset at 4:49 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:58 pm EST.

How long on average sun shines in December?

In December, the average sunshine duration is 3.3h.

What is the month with the lowest UV index?

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

What is the UV index reading in December?

In Heilwood, the average daily maximum UV index in December is 1. A UV Index reading of 2, and below, represents a minimal health vulnerability 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
Heilwood, PA

Average temperature in December - Heilwood, PA
  • Average high temperature in December: 36.5°F

The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (30.4°F).

  • Average low temperature in December: 26.4°F

The month with the highest average low temperature is July (58.8°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

Average pressure in December
Heilwood, PA

Average pressure in December - Heilwood, 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
Heilwood, PA

Average wind speed in December - Heilwood, PA
  • Average wind speed in December: 9.2mph

The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in December
Heilwood, PA

Average humidity in December - Heilwood, PA
  • Average humidity in December: 85%

The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are April, June, July and August (78%).

Average rainfall in December
Heilwood, PA

Average rainfall in December - Heilwood, PA
  • Average rainfall in December: 0.94"

The wettest month (with the highest rainfall) is May (1.26").
The driest month (with the least rainfall) is September (0.55").

Average rainfall days in December
Heilwood, PA

Average rainfall days in December - Heilwood, PA
  • Average rainfall days in December: 7.2 days

The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is January (5.8 days).

Average snowfall in December
Heilwood, PA

Average snowfall in December - Heilwood, PA
  • Average snowfall in December: 2.01"

The month with the highest snowfall is January (2.64").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Heilwood, PA

Average snowfall days in December - Heilwood, PA
  • Average snowfall days in December: 9.2 days

The month with the highest number of snowfall days is January (12.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Heilwood, 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 18min).

  • Average sunshine in December: 3h and 2min

The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).

Average sunshine days in December
Heilwood, PA

Average sunshine days in December - Heilwood, PA
  • Average sunshine days in December: 17.6 days

The month with the most sunshine days is November (19.9 days).
The month with the least sunshine days is May (12.3 days).

Average UV index in December
Heilwood, PA

Average UV index in December - Heilwood, 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
Heilwood, PA

Average cloud cover in December - Heilwood, PA
  • Average cloud cover in December: 68

The month with the most cloud cover is January (Cloud cover 72).
The month with the least cloud cover is August (Cloud cover 38).

Average visibility in December
Heilwood, PA

Average visibility in December - Heilwood, PA
  • Average visibility in December: 5mi

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

Heilwood, Pennsylvania, USA

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