December weather forecastGeneseo, IL
December
Weather in December
The first month of the winter, December, is still a cold month in Geneseo, Illinois, with an average temperature fluctuating between 34.5°F (1.4°C) and 24.1°F (-4.4°C).Temperature
Onset of December comes with a temperature decline, the average high falling from a frosty 46.9°F (8.3°C) in November to a cold 34.5°F (1.4°C). During December, an average low-temperature of 24.1°F (-4.4°C) is observed.Humidity
In Geneseo, the average relative humidity in December is 82%.Rainfall
The months with the least rainfall are January and December Rain falls for 5.5 days and accumulates 0.63" (16mm) of rain.Snowfall
Months with snowfall are January through April, October through December. In Geneseo, in December, during 5.7 snowfall days, 0.94" (24mm) of snow is typically accumulated. In Geneseo, during the entire year, snow falls for 29.3 days and aggregates up to 6.54" (166mm) of snow.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:08 am and sunset at 4:31 pm. On the last day of the month, sunrise is at 7:26 am and sunset at 4:41 pm CST.
Sunshine
In December, the average sunshine in Geneseo is 4.3h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for average individuals.Note: In December, the UV index of 1 transforms into the following advice:
Although prolonged sun exposure does not typically bother most people, children, babies, and those with sensitive skin should always have protection. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Stay sun-safe with clothing that is both closely woven and worn loosely. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Geneseo, IL
- Average high temperature in December: 34.5°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (28°F).
- Average low temperature in December: 24.1°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 (16°F).
Average pressure in December
Geneseo, IL
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in December
Geneseo, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in December
Geneseo, IL
- Average humidity in December: 82%
The months with the highest relative humidity are January and July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Geneseo, IL
- Average rainfall in December: 0.63"
The wettest month (with the highest rainfall) is May (2.48").
The driest months (with the least rainfall) are January and December (0.63").
Average rainfall days in December
Geneseo, IL
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is February (3.9 days).
Average snowfall in December
Geneseo, IL
- Average snowfall in December: 0.94"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Geneseo, IL
- Average snowfall days in December: 5.7 days
The month with the highest number of snowfall days is January (9 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
Geneseo, IL
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in December
Geneseo, IL
- Average sunshine days in December: 20.9 days
The month with the most sunshine days is December (20.9 days).
The month with the least sunshine days is June (12 days).
Average UV index in December
Geneseo, IL
- Average UV index in December: 1
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Geneseo, IL
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in December
Geneseo, 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).
