December weather forecastThayer, IL
December
Weather in December
The first month of the winter, December, is also an icy month in Thayer, Illinois, with an average temperature fluctuating between 39.4°F (4.1°C) and 28.2°F (-2.1°C).Temperature
Thayer's December weather features a mild decline in high-temperatures, reducing from a cool 50.9°F (10.5°C) in November to a wintry 39.4°F (4.1°C). During December, Thayer's temperature falls to a steady low-temperature average of 28.2°F (-2.1°C).Humidity
The average relative humidity in December is 78%.Rainfall
The months with the least rainfall in Thayer are February and December Rain falls for 7.5 days and accumulates 1.26" (32mm) of rain.Snowfall
Months with snowfall are January through April, November and December. In Thayer, during December, snow falls for 6.1 days and regularly aggregates up to 1.34" (34mm) of snow. In Thayer, during the entire year, snow falls for 26.5 days and aggregates up to 6.5" (165mm) of snow.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year in Thayer.On the first day of December, sunrise is at 7:01 am and sunset at 4:35 pm. On the last day of the month, sunrise is at 7:19 am and sunset at 4:45 pm CST.
Sunshine
In December, the average sunshine is 4.7h.UV index
The months with the lowest UV index in Thayer 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 exposure to the Sun's UV rays for average individuals.Note: In December, the maximum UV index of 2 translates into these guidelines:
In contrast to children, who must always be shielded from the sun, most people can tolerate up to an hour of sun exposure without any burns. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Watch out! The Sun's UV radiation can be nearly magnified twofold due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Thayer, IL
- Average high temperature in December: 39.4°F
The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (34°F).
- Average low temperature in December: 28.2°F
The month with the highest average low temperature is July (66.7°F).
The coldest month (with the lowest average low temperature) is January (21.7°F).
Average pressure in December
Thayer, 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 (29.92"Hg).
Average wind speed in December
Thayer, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is July (6.1mph).
Average humidity in December
Thayer, IL
- Average humidity in December: 78%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Thayer, IL
- Average rainfall in December: 1.26"
The wettest month (with the highest rainfall) is June (2.83").
The driest months (with the least rainfall) are February and December (1.26").
Average rainfall days in December
Thayer, IL
- Average rainfall days in December: 7.5 days
The month with the highest number of rainy days is May (16.8 days).
The month with the least rainy days is February (6.4 days).
Average snowfall in December
Thayer, IL
- Average snowfall in December: 1.34"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Thayer, IL
- Average snowfall days in December: 6.1 days
The month with the highest number of snowfall days is January (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
Thayer, IL
- Average daylight in December: 9h and 24min
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 24min).
- Average sunshine in December: 4h and 42min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Thayer, IL
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (18.8 days).
The month with the least sunshine days is May (11.5 days).
Average UV index in December
Thayer, 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
Thayer, IL
- Average cloud cover in December: 51
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in December
Thayer, 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).
