December weather forecastSmithfield, IL
December
Weather in December
December, the first month of the winter in Smithfield, is also a wintry month, with an average temperature varying between 37°F (2.8°C) and 26.4°F (-3.1°C).Temperature
A moderate decline in the average high-temperature is seen during December, decreasing from a frosty 49.1°F (9.5°C) in November to a wintry 37°F (2.8°C). Smithfield, during the nights of December, experiences an average temperature drop to a subzero cold 26.4°F (-3.1°C).Humidity
In December, the average relative humidity is 79%.Rainfall
December is the month with the least rainfall in Smithfield. Rain falls for 6.5 days and accumulates 0.94" (24mm) of precipitation.Snowfall
January through April, October through December are months with snowfall. In Smithfield, in December, during 5 snowfall days, 1.1" (28mm) of snow is typically accumulated. In Smithfield, Illinois, during the entire year, snow falls for 27.4 days and aggregates up to 9.21" (234mm) of snow.Daylight
The month with the shortest days in Smithfield is December, with an average of 9h and 18min of daylight.On the first day of the month, sunrise is at 7:05 am and sunset at 4:35 pm. On the last day of December, in Smithfield, sunrise is at 7:24 am and sunset at 4:44 pm CST.
Sunshine
In December, the average sunshine 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 value of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: The UV index of 2 in December translates into these instructions:
Although prolonged sun exposure does not typically bother most people, children, babies, and those with sensitive skin should always have protection. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. Take careful note! The UV radiation of the Sun can be nearly doubled by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Smithfield, IL
- Average high temperature in December: 37°F
The warmest month (with the highest average high temperature) is July (82.8°F).
The month with the lowest average high temperature is January (31.5°F).
- Average low temperature in December: 26.4°F
The month with the highest average low temperature is July (65.8°F).
The coldest month (with the lowest average low temperature) is January (19.4°F).
Average pressure in December
Smithfield, 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
Smithfield, IL
- Average wind speed in December: 9.8mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.5mph).
Average humidity in December
Smithfield, IL
- Average humidity in December: 79%
The month with the highest relative humidity is July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Smithfield, IL
- Average rainfall in December: 0.94"
The wettest month (with the highest rainfall) is May (3.23").
The driest month (with the least rainfall) is December (0.94").
Average rainfall days in December
Smithfield, IL
- Average rainfall days in December: 6.5 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is February (4.7 days).
Average snowfall in December
Smithfield, IL
- Average snowfall in December: 1.1"
The month with the highest snowfall is January (3.35").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Smithfield, IL
- Average snowfall days in December: 5 days
The month with the highest number of snowfall days is January (9.4 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
Smithfield, IL
- Average daylight in December: 9h and 18min
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 30min
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
Smithfield, IL
- Average sunshine days in December: 20.4 days
The month with the most sunshine days is December (20.4 days).
The month with the least sunshine days is June (11.1 days).
Average UV index in December
Smithfield, 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
Smithfield, IL
- Average cloud cover in December: 52
The month with the most cloud cover is January (Cloud cover 56).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in December
Smithfield, 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).
