December weather forecast
Greenville, IL

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Weather in December

December, the first month of the winter in Greenville, is also a wintry month, with an average temperature ranging between min 29.8°F (-1.2°C) and max 41.5°F (5.3°C).

Temperature

December comes with a decrease in the average high-temperature, falling from a cool 51.8°F (11°C) in November to an icy 41.5°F (5.3°C). During the month of December, the nighttime temperature falls to an average of 29.8°F (-1.2°C).

Humidity

In December, the average relative humidity is 78%.

Rainfall

In Greenville, in December, during 7.2 rainfall days, 1.61" (41mm) of precipitation is typically accumulated. In Greenville, during the entire year, the rain falls for 137.9 days and collects up to 24.88" (632mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. December is the month with the most snowfall. Snow falls for 4.1 days and accumulates 1.89" (48mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 30min of daylight.
On the first day of December, sunrise is at 6:57 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:45 pm CST.

Sunshine

In Greenville, the average sunshine in December is 4.7h.

UV index

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for the ordinary person.
Note: An average maximum UV index of 2 in December leads to these recommendations:
People with sensitive skin, children, and babies should always be protected from prolonged sun exposure. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Updated: Jul 25, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

Is it cold during December?

The average high-temperature and low-temperature during December are 41.5°F (5.3°C) and 29.8°F (-1.2°C) respectively. The average heat index (a.k.a. 'feels like', 'apparent temperature'), which factors the actual air temperature with the relative humidity, in August is computed to be 91.4°F (33°C).

What is the average humidity in December?

In December, the average relative humidity is 78%.

How many days does it rain in December?

In Greenville, in December, it is raining for 7.2 days, with typically 1.61" (41mm) of accumulated precipitation.

What is the snowiest month?

December is the month with the most snowfall. Snow falls for 4.1 days and accumulates 1.89" (48mm) of snow.

How many days does it snow in December?

In Greenville, during December, snow falls for 4.1 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 30min 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 30min.

What time are sunrise and sunset in December?

On the first day of December, sunrise is at 6:57 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:45 pm CST.

How many hours of sunshine does Greenville have in December?

In Greenville, Illinois, the average sunshine duration in December is 4.7h.

What is the month with the lowest UV index?

The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.

What is the UV index intensity in December?

In Greenville, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal hazard to health 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
Greenville, IL

Average temperature in December - Greenville, IL
  • Average high temperature in December: 41.5°F

The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is January (36.1°F).

  • Average low temperature in December: 29.8°F

The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).

Average pressure in December
Greenville, IL

Average pressure in December - Greenville, IL
  • Average pressure in December: 30.13"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Greenville, IL

Average wind speed in December - Greenville, IL
  • Average wind speed in December: 9.2mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).

Average humidity in December
Greenville, IL

Average humidity in December - Greenville, IL
  • Average humidity in December: 78%

The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).

Average rainfall in December
Greenville, IL

Average rainfall in December - Greenville, IL
  • Average rainfall in December: 1.61"

The wettest month (with the highest rainfall) is June (3.43").
The driest month (with the least rainfall) is February (1.26").

Average rainfall days in December
Greenville, IL

Average rainfall days in December - Greenville, IL
  • Average rainfall days in December: 7.2 days

The month with the highest number of rainy days is May (17.2 days).
The month with the least rainy days is January (6.3 days).

Average snowfall in December
Greenville, IL

Average snowfall in December - Greenville, IL
  • Average snowfall in December: 1.89"

The month with the highest snowfall is December (1.89").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in December
Greenville, IL

Average snowfall days in December - Greenville, IL
  • Average snowfall days in December: 4.1 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 and September (0 days).

Average daylight in December /
Average sunshine in December
Greenville, IL

Average daylight in December / Average sunshine in December - Greenville, IL
  • Average daylight in December: 9h and 3min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).

  • Average sunshine in December: 4h and 4min

The month with the most sunshine is June (Average sunshine: 10h and 24min).
The months with the least sunshine are January and February (Average sunshine: 4h and 30min).

Average sunshine days in December
Greenville, IL

Average sunshine days in December - Greenville, IL
  • Average sunshine days in December: 20 days

The month with the most sunshine days is December (20 days).
The month with the least sunshine days is May (11.8 days).

Average UV index in December
Greenville, IL

Average UV index in December - Greenville, IL
  • Average UV index in December: 2

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

Average cloud cover in December
Greenville, IL

Average cloud cover in December - Greenville, IL
  • Average cloud cover in December: 50

The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).

Average visibility in December
Greenville, IL

Average visibility in December - Greenville, IL
  • Average visibility in December: 6mi

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

Greenville, Illinois, USA

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