December weather forecast
Sibley, IL

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Weather in December

The first month of the winter, December, is still a cold month in Sibley, Illinois, with an average temperature fluctuating between 36.5°F (2.5°C) and 27°F (-2.8°C).

Temperature

Sibley's weather in December involves a decrease in the average high-temperature, moving down from November's chilly 47.8°F (8.8°C) to an icy 36.5°F (2.5°C). Sibley experiences an average nighttime temperature of 27°F (-2.8°C) in the month of December.

Humidity

The average relative humidity in December is 80%.

Rainfall

The months with the least rainfall in Sibley are February and December Rain falls for 6.1 days and accumulates 0.75" (19mm) of rain.

Snowfall

January through April, October through December are months with snowfall. In Sibley, during December, snow falls for 6.5 days and regularly aggregates up to 0.83" (21mm) of snow. In Sibley, during the entire year, snow falls for 29.4 days and aggregates up to 4.69" (119mm) of snow.

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 6:58 am and sunset at 4:27 pm. On the last day of December, sunrise is at 7:16 am and sunset at 4:36 pm CST.

Sunshine

In Sibley, the average sunshine in December is 4.2h.

UV index

December is the month with the lowest UV index, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV radiation for ordinary individuals.
Note: The average daily UV index of 1 in December transforms into the following instructions:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. During bright days, sunglasses that offer UVA and UVB defense are recommended. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Updated: Jun 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is December?

In December, in Sibley, the average high-temperature is 36.5°F (2.5°C), and the average low-temperature is 27°F (-2.8°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which combines air temperature and relative humidity, in July is computed to be 86°F (30°C).

What is the average humidity in December?

In December, the average relative humidity is 80%.

What is the driest month?

February and December are months with the least rain when the rain falls for 6.1 days and typically aggregates up to 0.75" (19mm) of rain.

How much does it rain in December?

In December, the rain falls for 6.1 days. Throughout December, 0.75" (19mm) of precipitation is accumulated.

How many days does it snow in December?

In Sibley, Illinois, during December, snow falls for 6.5 days and regularly aggregates up to 0.83" (21mm) of snow.

What is the month with the shortest days?

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

How many hours of daylight does Sibley have in December?

In December, the average day length is 9h and 20min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 6:58 am and sunset at 4:27 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 4:36 pm CST.

How many hours of sunshine does Sibley have in December?

In December, the average sunshine duration is 4.2h.

When is the lowest UV index?

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

What is the UV index reading in December?

The average daily maximum UV index in December is 1. A UV Index estimate of 2, and below, represents a low health risk from unsafe exposure to Sun's UV rays.
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
Sibley, IL

Average temperature in December - Sibley, IL
  • Average high temperature in December: 36.5°F

The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in December: 27°F

The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (19.6°F).

Average pressure in December
Sibley, IL

Average pressure in December - Sibley, IL
  • Average pressure in December: 30.11"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in December
Sibley, IL

Average wind speed in December - Sibley, IL
  • Average wind speed in December: 10.4mph

The windiest month (with the highest average wind speed) is January (11mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).

Average humidity in December
Sibley, IL

Average humidity in December - Sibley, IL
  • Average humidity in December: 80%

The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).

Average rainfall in December
Sibley, IL

Average rainfall in December - Sibley, IL
  • Average rainfall in December: 0.75"

The wettest month (with the highest rainfall) is May (1.93").
The driest months (with the least rainfall) are February and December (0.75").

Average rainfall days in December
Sibley, IL

Average rainfall days in December - Sibley, IL
  • Average rainfall days in December: 6.1 days

The month with the highest number of rainy days is May (14.9 days).
The month with the least rainy days is January (4.8 days).

Average snowfall in December
Sibley, IL

Average snowfall in December - Sibley, IL
  • Average snowfall in December: 0.83"

The month with the highest snowfall is January (1.38").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Sibley, IL

Average snowfall days in December - Sibley, IL
  • Average snowfall days in December: 6.5 days

The month with the highest number of snowfall days is January (9.3 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
Sibley, IL

Average daylight in December / Average sunshine in December - Sibley, IL
  • 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 1min

The month with the most sunshine is June (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in December
Sibley, IL

Average sunshine days in December - Sibley, IL
  • Average sunshine days in December: 18.5 days

The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is July (10.3 days).

Average UV index in December
Sibley, IL

Average UV index in December - Sibley, IL
  • Average UV index in December: 1

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in December
Sibley, IL

Average cloud cover in December - Sibley, IL
  • Average cloud cover in December: 56

The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 33).

Average visibility in December
Sibley, IL

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

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

Sibley, Illinois, USA

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