December weather forecastJohnston City, IL
December
Weather in December
The first month of the winter, December, is also a frosty month in Johnston City, Illinois, with temperature in the range of an average low of 31.5°F (-0.3°C) and an average high of 43.7°F (6.5°C).Temperature
The shift from November to December corresponds with a decrease in the average high-temperature, down to a frosty 43.7°F (6.5°C) from a fresh 53.8°F (12.1°C). During the month of December, the temperature generally drops to a low average of 31.5°F (-0.3°C).Humidity
In December, the average relative humidity is 78%.Rainfall
In Johnston City, during December, the rain falls for 10.3 days and regularly aggregates up to 2.56" (65mm) of precipitation. In Johnston City, during the entire year, the rain falls for 167.2 days and collects up to 37.68" (957mm) of precipitation.Snowfall
January through April, October through December are months with snowfall in Johnston City, Illinois. In Johnston City, Illinois, during December, snow falls for 4.1 days and regularly aggregates up to 1.34" (34mm) of snow. Throughout the year, in Johnston City, there are 19.8 snowfall days, and 6.57" (167mm) of snow is accumulated.Daylight
December has the shortest days of the year in Johnston City, with an average of 9h and 36min of daylight.On the first day of December, sunrise is at 6:53 am and sunset at 4:36 pm. On the last day of the month, sunrise is at 7:11 am and sunset at 4:46 pm CST.
Sunshine
In December, the average sunshine in Johnston City is 4.8h.UV index
January, February and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a minimal health hazard from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
Those with sensitive skin, infants, and children require constant safeguarding from prolonged sun exposure. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. Stay sun-safe with clothing that is both closely woven and worn loosely. Consider carefully! The reflective quality of snow can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Johnston City, IL
- Average high temperature in December: 43.7°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (39°F).
- Average low temperature in December: 31.5°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in December
Johnston City, IL
- Average pressure in December: 30.14"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Johnston City, IL
- Average wind speed in December: 8.9mph
The windiest months (with the highest average wind speed) are January and February (9.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in December
Johnston City, IL
- Average humidity in December: 78%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Johnston City, IL
- Average rainfall in December: 2.56"
The wettest month (with the highest rainfall) is April (4.92").
The driest month (with the least rainfall) is September (1.97").
Average rainfall days in December
Johnston City, IL
- Average rainfall days in December: 10.3 days
The month with the highest number of rainy days is May (18.5 days).
The month with the least rainy days is January (9.7 days).
Average snowfall in December
Johnston City, IL
- Average snowfall in December: 1.34"
The month with the highest snowfall is February (1.93").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Johnston City, IL
- Average snowfall days in December: 4.1 days
The month with the highest number of snowfall days is January (6.1 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
Johnston City, IL
- Average daylight in December: 9h and 36min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in December: 4h and 48min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in December
Johnston City, IL
- Average sunshine days in December: 17 days
The month with the most sunshine days is October (17.6 days).
The month with the least sunshine days is June (9.9 days).
Average UV index in December
Johnston City, 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 and December (UV index 2).
Average cloud cover in December
Johnston City, IL
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in December
Johnston City, 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).
