December weather forecast
Pottstown, PA

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Weather in December

December, the first month of the winter in Pottstown, is also a wintry month, with an average temperature varying between 30.2°F (-1°C) and 41.5°F (5.3°C).

Temperature

The arrival of December corresponds with a temperature reduction, down from November's cool 50.7°F (10.4°C) to an icy 41.5°F (5.3°C). In December, the recorded average low-temperature is a freezing cold 30.2°F (-1°C).

Humidity

In Pottstown, the average relative humidity in December is 79%.

Rainfall

In December, the rain falls for 9.5 days. Throughout December, 2.32" (59mm) of precipitation is accumulated. In Pottstown, during the entire year, the rain falls for 146.5 days and collects up to 27.87" (708mm) of precipitation.

Snowfall

Months with snowfall in Pottstown are January through April, November and December. In Pottstown, in December, snow falls for 2.7 days, with typically accumulated 1.89" (48mm) of snow. In Pottstown, during the entire year, snow falls for 19.1 days and aggregates up to 11.54" (293mm) of snow.

Daylight

With an average of 9h and 24min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:06 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:46 pm EST.

Sunshine

In Pottstown, the average sunshine in December is 4.9h.

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 reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for the average person.
Note: The daily high UV index of 2 during December translates into the following recommendations:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.

Frequently asked questions

How cold is it in December?

In Pottstown, 41.5°F (5.3°C) is the average high-temperature and 30.2°F (-1°C) is the average low-temperature during December. In August, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which combines air temperature and relative humidity, is estimated at 87.8°F (31°C).

What is the average humidity in December?

In December, the average relative humidity is 79%.

How many days does it rain in December?

In Pottstown, during December, the rain falls for 9.5 days and regularly aggregates up to 2.32" (59mm) of precipitation.

How many days does it snow in December?

In Pottstown, during December, snow falls for 2.7 days and regularly aggregates up to 1.89" (48mm) of snow.

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 in Pottstown.

What is the average length of the day in December?

The average day length in December is 9h and 22min.

When are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:06 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:46 pm EST.

How many hours of sunshine does Pottstown have in December?

In Pottstown, the average sunshine duration in December is 4.9h.

What is the month with the lowest UV index?

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 intensity in December?

In December, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a minimal hazard to health from unprotected exposure to 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
Pottstown, PA

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

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.4°F).

  • Average low temperature in December: 30.2°F

The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (23.2°F).

Average pressure in December
Pottstown, PA

Average pressure in December - Pottstown, 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).

Average wind speed in December
Pottstown, PA

Average wind speed in December - Pottstown, PA
  • Average wind speed in December: 7.6mph

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
Pottstown, PA

Average humidity in December - Pottstown, PA
  • Average humidity in December: 79%

The months with the highest relative humidity are February and October (80%).
The months with the lowest relative humidity are April and July (75%).

Average rainfall in December
Pottstown, PA

Average rainfall in December - Pottstown, PA
  • Average rainfall in December: 2.32"

The wettest month (with the highest rainfall) is August (3.15").
The driest month (with the least rainfall) is September (1.81").

Average rainfall days in December
Pottstown, PA

Average rainfall days in December - Pottstown, PA
  • Average rainfall days in December: 9.5 days

The months with the highest number of rainy days are May and July (17 days).
The month with the least rainy days is January (7.3 days).

Average snowfall in December
Pottstown, PA

Average snowfall in December - Pottstown, PA
  • Average snowfall in December: 1.89"

The month with the highest snowfall is March (3.7").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in December
Pottstown, PA

Average snowfall days in December - Pottstown, PA
  • Average snowfall days in December: 2.7 days

The month with the highest number of snowfall days is January (5.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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

Average daylight in December / Average sunshine in December - Pottstown, 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 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

Average sunshine days in December
Pottstown, PA

Average sunshine days in December - Pottstown, PA
  • Average sunshine days in December: 19.4 days

The month with the most sunshine days is November (21 days).
The month with the least sunshine days is May (12.3 days).

Average UV index in December
Pottstown, PA

Average UV index in December - Pottstown, 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
Pottstown, PA

Average cloud cover in December - Pottstown, PA
  • Average cloud cover in December: 48

The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 32).

Average visibility in December
Pottstown, PA

Average visibility in December - Pottstown, 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).

Pottstown, Pennsylvania, USA

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