December weather forecast
Joliett, PA

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Weather in December

December, the first month of the winter in Joliett, is also an icy month, with an average temperature fluctuating between 28.2°F (-2.1°C) and 39.7°F (4.3°C).

Temperature

December's arrival coincides with a drop in the average high-temperature, decreasing from November's frosty 48.7°F (9.3°C) to a wintry 39.7°F (4.3°C). In the month of December, the average low-temperature usually rests at a freezing cold 28.2°F (-2.1°C).

Humidity

In December, the average relative humidity in Joliett is 81%.

Rainfall

In Joliett, in December, it is raining for 9.5 days, with typically 1.02" (26mm) of accumulated precipitation. In Joliett, Pennsylvania, during the entire year, the rain falls for 133.5 days and collects up to 15.16" (385mm) of precipitation.

Snowfall

Months with snowfall in Joliett are January through May, October through December. In Joliett, Pennsylvania, in December, snow falls for 3.9 days, with typically accumulated 0.91" (23mm) of snow. Throughout the year, in Joliett, there are 23.2 snowfall days, and 5.67" (144mm) of snow is accumulated.

Daylight

December has the shortest days of the year, with an average of 9h and 18min of daylight.
On the first day of December in Joliett, sunrise is at 7:10 am and sunset at 4:39 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:48 pm EST.

Sunshine

In December, the average sunshine in Joliett is 4.4h.

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 value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum UV index, 2 during December, leads to the following recommendations:
While sun exposure does not greatly affect most, individuals with fair skin, babies, and children always need vigilant safeguarding. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears. Consider carefully! The reflective quality of snow can almost double the intensity of the Sun's UV radiation.
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Frequently asked questions

Is it cold in Joliett during December?

During December, Joliett experiences an average high-temperature of 39.7°F (4.3°C) and a low-temperature of 28.2°F (-2.1°C). In July, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is estimated at 87.8°F (31°C).

What is the average humidity in December in Joliett?

In December, the average relative humidity is 81%.

How many days does it rain in December in Joliett?

In Joliett, during December, the rain falls for 9.5 days and regularly aggregates up to 1.02" (26mm) of precipitation.

How many days does it snow in December in Joliett?

In December, in Joliett, it is snowing for 3.9 days. Throughout December, 0.91" (23mm) of snow is accumulated.

What is the month with the shortest days in Joliett?

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

How many hours of daylight does Joliett have in December?

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

When are sunrise and sunset in December in Joliett?

On the first day of December in Joliett, sunrise is at 7:10 am and sunset at 4:39 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:48 pm EST.

How many hours of sunshine does Joliett have in December?

The average sunshine duration in December is 4.4h.

When is the lowest UV index in Joliett?

The months with the lowest UV index in Joliett are January through March, November and December, with an average maximum UV index of 2.

What is the UV index reading in December in Joliett?

In Joliett, the average daily maximum UV index in December is 2. A UV Index estimate of 2, and below, represents a low health threat 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
Joliett, PA

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

The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in December: 28.2°F

The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).

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Average pressure in December
Joliett, PA

Average pressure in December - Joliett, 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 (29.94"Hg).

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Average wind speed in December
Joliett, PA

Average wind speed in December - Joliett, PA
  • Average wind speed in December: 7.8mph

The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

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Average humidity in December
Joliett, PA

Average humidity in December - Joliett, PA
  • Average humidity in December: 81%

The month with the highest relative humidity is February (82%).
The months with the lowest relative humidity are March and April (77%).

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Average rainfall in December
Joliett, PA

Average rainfall in December - Joliett, PA
  • Average rainfall in December: 1.02"

The wettest month (with the highest rainfall) is August (1.93").
The driest month (with the least rainfall) is February (0.83").

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Average rainfall days in December
Joliett, PA

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

The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is January (6.8 days).

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Average snowfall in December
Joliett, PA

Average snowfall in December - Joliett, PA
  • Average snowfall in December: 0.91"

The month with the highest snowfall is January (1.77").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in December
Joliett, PA

Average snowfall days in December - Joliett, PA
  • Average snowfall days in December: 3.9 days

The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Joliett, 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: 4h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).

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Average sunshine days in December
Joliett, PA

Average sunshine days in December - Joliett, PA
  • Average sunshine days in December: 18.3 days

The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is May (12.7 days).

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Average UV index in December
Joliett, PA

Average UV index in December - Joliett, PA
  • Average UV index in December: 2

The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

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Average cloud cover in December
Joliett, PA

Average cloud cover in December - Joliett, PA
  • Average cloud cover in December: 53

The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 33).

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Average visibility in December
Joliett, PA

Average visibility in December - Joliett, PA
  • Average visibility in December: 6mi

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

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Joliett, Pennsylvania, USA

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