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 shift from November to December involves a decrease in the average high-temperature, dropping from a fresh 52.3°F (11.3°C) to a wintry 41.5°F (5.3°C). During the month of December, the nighttime temperature falls to an average of 30°F (-1.1°C).Humidity
In December, the average relative humidity is 77%.Rainfall
In Saint Jacob, in December, it is raining for 5.9 days, with typically 0.79" (20mm) of accumulated precipitation. In Saint Jacob, during the entire year, the rain falls for 110.6 days and collects up to 12.01" (305mm) of precipitation.Snowfall
January through March, October through December are months with snowfall. The month with the most snowfall is December, when snow falls for 3.1 days and typically aggregates up to 0.94" (24mm) of snow.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year in Saint Jacob.On the first day of the month, sunrise is at 6:58 am and sunset at 4:37 pm. On the last day of December, in Saint Jacob, Illinois, sunrise is at 7:16 am and sunset at 4:47 pm CST.
Sunshine
In Saint Jacob, the average sunshine in December is 4.8h.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 of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the ordinary person.Note: A maximum daily UV index of 2 during December morphs into the following directions:
Prolonged exposure to sunlight rarely troubles the majority, but constant protection is vital for babies, children, and fair-skinned people. For health reasons, it's advisable to reduce direct sun exposure during peak hours around midday. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What is the average humidity in December?
How much does it rain in December?
What is the snowiest month in Saint Jacob?
How much does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Saint Jacob have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Saint Jacob, IL
- Average high temperature in December: 41.5°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (36.9°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (23.7°F).
Average pressure in December
Saint Jacob, 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
Saint Jacob, IL
- Average wind speed in December: 8.9mph
The windiest month (with the highest average wind speed) is January (9.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in December
Saint Jacob, IL
- Average humidity in December: 77%
The months with the highest relative humidity are July and August (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Saint Jacob, IL
- Average rainfall in December: 0.79"
The wettest month (with the highest rainfall) is May (1.46").
The driest month (with the least rainfall) is February (0.55").
Average rainfall days in December
Saint Jacob, IL
- Average rainfall days in December: 5.9 days
The month with the highest number of rainy days is May (13.1 days).
The months with the least rainy days are January and December (5.9 days).
Average snowfall in December
Saint Jacob, IL
- Average snowfall in December: 0.94"
The month with the highest snowfall is December (0.94").
The months with the least snowfall are April, May, June, July, August and September (0").
Average snowfall days in December
Saint Jacob, IL
- Average snowfall days in December: 3.1 days
The months with the highest number of snowfall days are January and February (4.8 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
Saint Jacob, IL
- Average daylight in December: 9h and 3min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is June (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 36min).
Average sunshine days in December
Saint Jacob, IL
- Average sunshine days in December: 21.8 days
The month with the most sunshine days is December (21.8 days).
The month with the least sunshine days is July (14.5 days).
Average UV index in December
Saint Jacob, IL
- Average UV index in December: 2
The months with the highest UV index are May, 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 Jacob, IL
- Average cloud cover in December: 49
The months with the most cloud cover are January and February (Cloud cover 50).
The months with the least cloud cover are June, July, August and September (Cloud cover 28).
Average visibility in December
Saint Jacob, 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).
Saint Jacob, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location