December weather forecast
Rockbridge, IL

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Weather in December

The first month of the winter, December, is still a cold month in Rockbridge, Illinois, with an average temperature fluctuating between 40.5°F (4.7°C) and 28.6°F (-1.9°C).

Temperature

December brings a decrease in the average high-temperature, shifting from a cool 51.6°F (10.9°C) in November to an icy 40.5°F (4.7°C). Rockbridge temperatures generally rest at a low of 28.6°F (-1.9°C) during the December nights.

Humidity

In Rockbridge, the average relative humidity in December is 77%.

Rainfall

In Rockbridge, during December, the rain falls for 6.4 days and regularly aggregates up to 0.75" (19mm) of precipitation. In Rockbridge, during the entire year, the rain falls for 120.6 days and collects up to 14.17" (360mm) of precipitation.

Snowfall

January through March, November and December are months with snowfall. In Rockbridge, in December, snow falls for 3.7 days, with typically accumulated 0.83" (21mm) of snow. Throughout the year, there are 19.1 snowfall days, and 3.82" (97mm) of snow is accumulated.

Daylight

With an average of 9h and 30min of daylight, December has the shortest days of the year in Rockbridge.
On the first day of December, sunrise is at 7:02 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:47 pm CST.

Sunshine

In Rockbridge, Illinois, the average sunshine in December is 4.9h.

UV index

The months with the lowest UV index in Rockbridge are January, February, November and December, with an average maximum UV index of 2. A UV Index value of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the ordinary person.
Note: An average maximum UV index of 2 in December leads to these recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Arm yourself against UV rays' harm with protective apparel and UV-filtering shades. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
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Frequently asked questions

How cold is it in Rockbridge in December?

During December, Rockbridge experiences an average high-temperature of 40.5°F (4.7°C) and a low-temperature of 28.6°F (-1.9°C). In August, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which factors the actual air temperature with the relative humidity, is evaluated at 91.4°F (33°C).

What is the average humidity in December in Rockbridge?

In December, the average relative humidity is 77%.

How many days does it rain in December in Rockbridge?

In December, in Rockbridge, Illinois, the rain falls for 6.4 days. Throughout December, 0.75" (19mm) of precipitation is accumulated.

How much does it snow in Rockbridge in December?

In December, in Rockbridge, it is snowing for 3.7 days. Throughout December, 0.83" (21mm) of snow is accumulated.

What is the month with the shortest days in Rockbridge?

With an average of 9h and 30min of daylight, December has the shortest days of the year in Rockbridge.

What is the average length of the day in December in Rockbridge?

In December, the average day length is 9h and 28min.

When is the sunrise / sunset in December in Rockbridge?

In December, on the first day of the month, sunrise is at 7:02 am and sunset at 4:38 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:47 pm CST.

How many hours of sunshine does Rockbridge have in December?

In December, the average sunshine duration is 4.9h.

What are the months with the lowest UV index in Rockbridge?

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

What is the UV index reading in December in Rockbridge?

In Rockbridge, Illinois, the average daily maximum UV index in December is 2. A UV Index value of 2, and less, symbolizes a low health threat 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
Rockbridge, IL

Average temperature in December - Rockbridge, IL
  • Average high temperature in December: 40.5°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 (35.2°F).

  • Average low temperature in December: 28.6°F

The month with the highest average low temperature is July (67.3°F).
The coldest month (with the lowest average low temperature) is January (22.3°F).

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Average pressure in December
Rockbridge, IL

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

The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

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Average wind speed in December
Rockbridge, IL

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

The windiest month (with the highest average wind speed) is January (9.7mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).

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Average humidity in December
Rockbridge, IL

Average humidity in December - Rockbridge, IL
  • Average humidity in December: 77%

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

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Average rainfall in December
Rockbridge, IL

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

The wettest month (with the highest rainfall) is June (1.93").
The driest month (with the least rainfall) is November (0.67").

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Average rainfall days in December
Rockbridge, IL

Average rainfall days in December - Rockbridge, IL
  • Average rainfall days in December: 6.4 days

The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (5.6 days).

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Average snowfall in December
Rockbridge, IL

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

The month with the highest snowfall is February (1.34").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in December
Rockbridge, IL

Average snowfall days in December - Rockbridge, IL
  • Average snowfall days in December: 3.7 days

The month with the highest number of snowfall days is January (6 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in December / Average sunshine in December - Rockbridge, 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 5min

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

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Average sunshine days in December
Rockbridge, IL

Average sunshine days in December - Rockbridge, IL
  • Average sunshine days in December: 21.7 days

The month with the most sunshine days is December (21.7 days).
The month with the least sunshine days is June (12.4 days).

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Average UV index in December
Rockbridge, IL

Average UV index in December - Rockbridge, 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).

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Average cloud cover in December
Rockbridge, IL

Average cloud cover in December - Rockbridge, IL
  • Average cloud cover in December: 48

The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are August and September (Cloud cover 28).

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Average visibility in December
Rockbridge, IL

Average visibility in December - Rockbridge, 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).

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Rockbridge, Illinois, USA

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