Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
The arrival of December corresponds with a shift in temperature, down from a fresh 51.8°F (11°C) in November to an icy 41°F (5°C). December nights in Vandalia, Illinois, are marked by an average low-temperature of 29.5°F (-1.4°C).Humidity
In Vandalia, the average relative humidity in December is 78%.Rainfall
In Vandalia, in December, during 9.7 rainfall days, 2.44" (62mm) of precipitation is typically accumulated. Throughout the year, there are 164.1 rainfall days, and 36.73" (933mm) of precipitation is accumulated.Snowfall
January through April, November and December are months with snowfall in Vandalia. The month with the most snowfall is December, when snow falls for 5.1 days and typically aggregates up to 2.4" (61mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of December in Vandalia, Illinois, sunrise is at 6:56 am and sunset at 4:34 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 4:44 pm CST.
Sunshine
The average sunshine in December in Vandalia is 4.6h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health vulnerability from exposure to the Sun's UV radiation for average individuals.Note: In December, the maximum UV index of 2 translates into these guidelines:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.
Frequently asked questions
How cold is December in Vandalia?
What is the average humidity in December in Vandalia?
How many days does it rain in December in Vandalia?
When does it snow the most in Vandalia?
How many days does it snow in December in Vandalia?
What is the month with the shortest days in Vandalia?
How many hours of daylight does Vandalia have in December?
When are sunrise and sunset in December in Vandalia?
How long on average sun shines in December in Vandalia?
What is the month with the lowest UV index in Vandalia?
What is the UV index reading in December in Vandalia?
Average temperature in December
Vandalia, IL
- Average high temperature in December: 41°F
The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (36°F).
- Average low temperature in December: 29.5°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 (23.4°F).
Average pressure in December
Vandalia, 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 (29.93"Hg).
Average wind speed in December
Vandalia, IL
- Average wind speed in December: 9.3mph
The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).
Average humidity in December
Vandalia, 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
Vandalia, IL
- Average rainfall in December: 2.44"
The wettest month (with the highest rainfall) is June (4.57").
The driest month (with the least rainfall) is February (2.01").
Average rainfall days in December
Vandalia, IL
- Average rainfall days in December: 9.7 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is January (9.2 days).
Average snowfall in December
Vandalia, IL
- Average snowfall in December: 2.4"
The month with the highest snowfall is December (2.4").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Vandalia, IL
- Average snowfall days in December: 5.1 days
The month with the highest number of snowfall days is January (8.3 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
Vandalia, 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 18min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in December
Vandalia, IL
- Average sunshine days in December: 16.6 days
The month with the most sunshine days is October (17.2 days).
The month with the least sunshine days is July (8.6 days).
Average UV index in December
Vandalia, 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
Vandalia, IL
- Average cloud cover in December: 51
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are June, July and September (Cloud cover 30).
Average visibility in December
Vandalia, 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).
Vandalia, Illinois, USA
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