December weather forecast
Atco, PA

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Weather in December

The first month of the winter, December, is also a wintry month in Atco, Pennsylvania, with an average temperature varying between 36°F (2.2°C) and 25°F (-3.9°C).

Temperature

In December, the average high-temperature decreases from a chilly 45.9°F (7.7°C) in November to a wintry 36°F (2.2°C). In December, Atco experiences an average nighttime temperature of 25°F (-3.9°C).

Humidity

With an average relative humidity of 85%, December is the most humid month.

Rainfall

In December, the rain falls for 8.5 days. Throughout December, 1.46" (37mm) of precipitation is accumulated. In Atco, during the entire year, the rain falls for 132.5 days and collects up to 19.21" (488mm) of precipitation.

Snowfall

Months with snowfall in Atco are January through May, October through December. The months with the most snowfall are January and December, with an average 3.27" (83mm) of accumulated snow.

Daylight

With an average of 9h and 12min of daylight, December has the shortest days of the year.
On the first day of December, sunrise is at 7:08 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:40 pm EST.

Sunshine

The average sunshine in December is 3.8h.

UV index

The month with the lowest UV index is December, with an average maximum UV index of 1. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: An average maximum UV index of 1 in December leads to these recommendations:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Stay sun-safe with clothing that is both closely woven and worn loosely. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
Updated: Aug 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

In Atco, 36°F (2.2°C) is the average high-temperature and 25°F (-3.9°C) is the average low-temperature during December. The average heat index (a.k.a. 'apparent temperature', 'feels like'), which factors the actual air temperature with the relative humidity, in July is computed to be 86°F (30°C).

What is the most humid month?

The most humid month is December, with an average relative humidity of 85%.

What is the average humidity in December?

The average relative humidity in December is 85%.

How much does it rain in December?

In Atco, during December, the rain falls for 8.5 days and regularly aggregates up to 1.46" (37mm) of precipitation.

When does it snow the most?

The months with the most snowfall are January and December, with an average 3.27" (83mm) of accumulated snow.

How many days does it snow in December?

In December, it is snowing for 8.2 days. Throughout December, 3.27" (83mm) of snow is accumulated.

What is the month with the shortest days?

December has the shortest days of the year, with an average of 9h and 12min of daylight.

How many hours of daylight does Atco have in December?

The average day length in December is 9h and 13min.

When are sunrise and sunset in December?

On the first day of December, sunrise is at 7:08 am and sunset at 4:30 pm. On the last day of the month, sunrise is at 7:27 am and sunset at 4:40 pm EST.

How many hours of sunshine does Atco have in December?

In Atco, the average sunshine duration in December is 3.8h.

When is 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 Atco, Pennsylvania, the average daily maximum UV index in December is 1. A UV Index of 2, and less, symbolizes 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
Atco, PA

Average temperature in December - Atco, PA
  • Average high temperature in December: 36°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (30.4°F).

  • Average low temperature in December: 25°F

The month with the highest average low temperature is July (58.6°F).
The coldest month (with the lowest average low temperature) is January (18°F).

Average pressure in December
Atco, PA

Average pressure in December - Atco, PA
  • Average pressure in December: 30.08"Hg

The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in December
Atco, PA

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

The windiest month (with the highest average wind speed) is February (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in December
Atco, PA

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

The month with the highest relative humidity is December (85%).
The month with the lowest relative humidity is July (77%).

Average rainfall in December
Atco, PA

Average rainfall in December - Atco, PA
  • Average rainfall in December: 1.46"

The wettest months (with the highest rainfall) are July and August (2.09").
The driest months (with the least rainfall) are January and September (1.14").

Average rainfall days in December
Atco, PA

Average rainfall days in December - Atco, PA
  • Average rainfall days in December: 8.5 days

The month with the highest number of rainy days is May (15.6 days).
The months with the least rainy days are January and February (6.9 days).

Average snowfall in December
Atco, PA

Average snowfall in December - Atco, PA
  • Average snowfall in December: 3.27"

The months with the highest snowfall are January and December (3.27").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Atco, PA

Average snowfall days in December - Atco, PA
  • Average snowfall days in December: 8.2 days

The month with the highest number of snowfall days is February (10.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Atco, PA
  • Average daylight in December: 9h and 1min

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 12min).

  • Average sunshine in December: 3h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 3h and 36min).

Average sunshine days in December
Atco, PA

Average sunshine days in December - Atco, PA
  • Average sunshine days in December: 15.2 days

The month with the most sunshine days is September (18.6 days).
The month with the least sunshine days is February (12.5 days).

Average UV index in December
Atco, PA

Average UV index in December - Atco, 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
Atco, PA

Average cloud cover in December - Atco, PA
  • Average cloud cover in December: 62

The months with the most cloud cover are February and December (Cloud cover 62).
The month with the least cloud cover is July (Cloud cover 38).

Average visibility in December
Atco, PA

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

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

Atco, Pennsylvania, USA

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