December weather forecast
Lemont, PA

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Weather in December

The first month of the winter, December, is also a wintry month in Lemont, Pennsylvania, with an average temperature varying between 36.9°F (2.7°C) and 26.4°F (-3.1°C).

Temperature

The onset of December brings a small change in high-temperatures, falling from a chilly 46.8°F (8.2°C) in November to an icy 36.9°F (2.7°C). December generally records an average low-temperature of 26.4°F (-3.1°C).

Humidity

February and December, with an average relative humidity of 84%, are the most humid months.

Rainfall

In Lemont, during December, the rain falls for 12.6 days and regularly aggregates up to 2.52" (64mm) of precipitation. In Lemont, during the entire year, the rain falls for 175.7 days and collects up to 30.94" (786mm) of precipitation.

Snowfall

Months with snowfall are January through May, October through December. In December, in Lemont, it is snowing for 11.5 days. Throughout December, 4.45" (113mm) of snow is accumulated. Throughout the year, there are 59 snowfall days, and 26.3" (668mm) 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 the month, sunrise is at 7:16 am and sunset at 4:44 pm. On the last day of December, sunrise is at 7:35 am and sunset at 4:53 pm EST.

Sunshine

In Lemont, the average sunshine in December is 3.7h.

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 unsafe exposure to UV radiation for the average person.
Note: In December, the maximum UV index of 1 suggests these recommendations:
For the majority, extended sun exposure is not of great concern. Infants and people with sensitive skin must always be protected. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses. Be on the lookout! Nearly twofold UV radiation from the Sun can be reflected by snow.
Updated: Jun 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in December?

The average high-temperature and low-temperature during December are 36.9°F (2.7°C) and 26.4°F (-3.1°C) respectively. The average heat index (a.k.a. 'feels like', 'real feel'), which represents the influence of relative humidity on air temperature, in July is evaluated at 87.8°F (31°C).

What are the most humid months?

February and December, with an average relative humidity of 84%, are most humid months.

What is the average humidity in December?

In Lemont, the average relative humidity in December is 84%.

How much does it rain in December?

In Lemont, in December, during 12.6 rainfall days, 2.52" (64mm) of precipitation is typically accumulated.

How much does it snow in December?

In December, it is snowing for 11.5 days. Throughout December, 4.45" (113mm) of snow is accumulated.

What is the month with the shortest days in Lemont?

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

What is the average length of the day in December?

In December, the average day length is 9h and 18min.

When is the sunrise / sunset in December?

In December, on the first day of the month, sunrise is at 7:16 am and sunset at 4:44 pm. On the last day of the month, in Lemont, Pennsylvania, sunrise is at 7:35 am and sunset at 4:53 pm EST.

How long on average sun shines in December?

In December, the average sunshine duration is 3.7h.

When is the lowest UV index in Lemont?

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

What is the UV index reading in December?

In Lemont, the average daily maximum UV index in December is 1. A UV Index value of 2, and less, symbolizes a low health risk 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
Lemont, PA

Average temperature in December - Lemont, PA
  • Average high temperature in December: 36.9°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (31.1°F).

  • Average low temperature in December: 26.4°F

The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is January (18.7°F).

Average pressure in December
Lemont, PA

Average pressure in December - Lemont, 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
Lemont, PA

Average wind speed in December - Lemont, PA
  • Average wind speed in December: 7.4mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).

Average humidity in December
Lemont, PA

Average humidity in December - Lemont, PA
  • Average humidity in December: 84%

The months with the highest relative humidity are February and December (84%).
The month with the lowest relative humidity is July (76%).

Average rainfall in December
Lemont, PA

Average rainfall in December - Lemont, PA
  • Average rainfall in December: 2.52"

The wettest month (with the highest rainfall) is May (3.5").
The driest month (with the least rainfall) is November (2.01").

Average rainfall days in December
Lemont, PA

Average rainfall days in December - Lemont, PA
  • Average rainfall days in December: 12.6 days

The month with the highest number of rainy days is May (19.4 days).
The month with the least rainy days is February (9.8 days).

Average snowfall in December
Lemont, PA

Average snowfall in December - Lemont, PA
  • Average snowfall in December: 4.45"

The month with the highest snowfall is February (6.77").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in December
Lemont, PA

Average snowfall days in December - Lemont, PA
  • Average snowfall days in December: 11.5 days

The month with the highest number of snowfall days is January (15.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Lemont, PA
  • Average daylight in December: 9h and 2min

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 18min).

  • Average sunshine in December: 3h and 4min

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

Average sunshine days in December
Lemont, PA

Average sunshine days in December - Lemont, PA
  • Average sunshine days in December: 12 days

The month with the most sunshine days is November (14.5 days).
The month with the least sunshine days is February (8.5 days).

Average UV index in December
Lemont, PA

Average UV index in December - Lemont, 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
Lemont, PA

Average cloud cover in December - Lemont, PA
  • Average cloud cover in December: 61

The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is July (Cloud cover 36).

Average visibility in December
Lemont, PA

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

The months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (5mi).
The month with the lowest visibility is February (4mi).

Lemont, Pennsylvania, USA

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