December weather forecast
Saint Augustine, IL

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Weather in December

The first month of the winter, December, is also a wintry month in Saint Augustine, Illinois, with an average temperature fluctuating between 25°F (-3.9°C) and 35.8°F (2.1°C).

Temperature

The arrival of December indicates a decrease in the average high-temperature, moving from a frosty 47.5°F (8.6°C) in November to an icy 35.8°F (2.1°C). During the month of December, Saint Augustine anticipates a mean low-temperature of 25°F (-3.9°C).

Humidity

In December, the average relative humidity is 81%.

Rainfall

January and December are months with the least rain when the rain falls for 6.8 days and typically aggregates up to 0.59" (15mm) of rain.

Snowfall

January through April, October through December are months with snowfall. In Saint Augustine, in December, snow falls for 7.1 days, with typically accumulated 0.75" (19mm) of snow. In Saint Augustine, during the entire year, snow falls for 32.2 days and aggregates up to 4.8" (122mm) of snow.

Daylight

The month with the shortest days is December, with an average of 9h and 18min of daylight.
On the first day of December, sunrise is at 7:06 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:25 am and sunset at 4:44 pm CST.

Sunshine

The average sunshine in December in Saint Augustine is 4.5h.

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 reading of 2, and below, represents a low threat to health from exposure to the Sun's UV radiation for the average person.
Note: A maximum UV index of 2 in December translates into the following recommendations:
Protection from prolonged sun exposure is necessary for babies, children, and individuals with sensitive skin. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Updated: Aug 22, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

How cold is it in Saint Augustine in December?

The high-temperature during December is 35.8°F (2.1°C) and the low-temperature is 25°F (-3.9°C). In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is calculated to be 87.8°F (31°C).

What is the average humidity in December?

The average relative humidity in December is 81%.

What is the driest month?

January and December are months with the least rain when the rain falls for 6.8 days and typically aggregates up to 0.59" (15mm) of rain.

How many days does it rain in December?

In Saint Augustine, in December, it is raining for 6.8 days, with typically 0.59" (15mm) of accumulated precipitation.

How many days does it snow in December?

In Saint Augustine, in December, snow falls for 7.1 days, with typically accumulated 0.75" (19mm) of snow.

What is the month with the shortest days?

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 Saint Augustine, the average day length in December is 9h and 19min.

What time are sunrise and sunset in December?

In December, on the first day of the month, sunrise is at 7:06 am and sunset at 4:34 pm. On the last day of the month, in Saint Augustine, sunrise is at 7:25 am and sunset at 4:44 pm CST.

How long on average sun shines in December?

In Saint Augustine, the average sunshine duration in December is 4.5h.

When is 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 Saint Augustine?

In Saint Augustine, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability 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
Saint Augustine, IL

Average temperature in December - Saint Augustine, IL
  • Average high temperature in December: 35.8°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (29.8°F).

  • Average low temperature in December: 25°F

The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).

Average pressure in December
Saint Augustine, IL

Average pressure in December - Saint Augustine, 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 (29.91"Hg).

Average wind speed in December
Saint Augustine, IL

Average wind speed in December - Saint Augustine, IL
  • Average wind speed in December: 9.9mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in December
Saint Augustine, IL

Average humidity in December - Saint Augustine, IL
  • Average humidity in December: 81%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).

Average rainfall in December
Saint Augustine, IL

Average rainfall in December - Saint Augustine, IL
  • Average rainfall in December: 0.59"

The wettest month (with the highest rainfall) is May (2.2").
The driest months (with the least rainfall) are January and December (0.59").

Average rainfall days in December
Saint Augustine, IL

Average rainfall days in December - Saint Augustine, IL
  • Average rainfall days in December: 6.8 days

The month with the highest number of rainy days is May (16.3 days).
The month with the least rainy days is February (4.4 days).

Average snowfall in December
Saint Augustine, IL

Average snowfall in December - Saint Augustine, IL
  • Average snowfall in December: 0.75"

The month with the highest snowfall is January (1.26").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in December
Saint Augustine, IL

Average snowfall days in December - Saint Augustine, IL
  • Average snowfall days in December: 7.1 days

The month with the highest number of snowfall days is January (10.3 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
Saint Augustine, IL

Average daylight in December / Average sunshine in December - Saint Augustine, 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 3min

The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in December
Saint Augustine, IL

Average sunshine days in December - Saint Augustine, IL
  • Average sunshine days in December: 18.1 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (11.2 days).

Average UV index in December
Saint Augustine, IL

Average UV index in December - Saint Augustine, 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
Saint Augustine, IL

Average cloud cover in December - Saint Augustine, IL
  • Average cloud cover in December: 53

The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 29).

Average visibility in December
Saint Augustine, IL

Average visibility in December - Saint Augustine, IL
  • Average visibility in December: 6mi

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

Saint Augustine, Illinois, USA

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