December weather forecastSaint Charles, MO
December
Weather in December
The first month of the winter, December, is also a wintry month in Saint Charles, Missouri, with an average temperature ranging between max 42.1°F (5.6°C) and min 30°F (-1.1°C).Temperature
Observing a mild shift, the average high-temperature during December reduces from November's fresh 53.2°F (11.8°C) to an icy 42.1°F (5.6°C). In December, Saint Charles encounters an average low-temperature of 30°F (-1.1°C) during the night.Humidity
In December, the average relative humidity is 76%.Rainfall
In Saint Charles, in December, it is raining for 7.3 days, with typically 1.73" (44mm) of accumulated precipitation. Throughout the year, there are 141.9 rainfall days, and 27.68" (703mm) of precipitation is accumulated.Snowfall
Months with snowfall in Saint Charles are January through March, November and December. In Saint Charles, during December, snow falls for 4.4 days and regularly aggregates up to 1.81" (46mm) of snow. Throughout the year, there are 21.6 snowfall days, and 6.73" (171mm) of snow is accumulated.Daylight
With an average of 9h and 30min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:01 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:20 am and sunset at 4:50 pm CST.
Sunshine
In December, the average sunshine is 4.9h.UV index
January, February and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index estimate of 2, and below, represents a minimal health hazard from unsafe exposure to UV radiation for the average person.Note: The daily high UV index of 2 during December translates into the following recommendations:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. On your guard! Snow's reflection 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
Saint Charles, MO
- Average high temperature in December: 42.1°F
The warmest month (with the highest average high temperature) is July (86.7°F).
The month with the lowest average high temperature is January (37.2°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (68.9°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in December
Saint Charles, MO
- 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 Charles, MO
- Average wind speed in December: 8.6mph
The windiest month (with the highest average wind speed) is January (9.3mph).
The calmest months (with the lowest average wind speed) are July and August (5.6mph).
Average humidity in December
Saint Charles, MO
- Average humidity in December: 76%
The month with the highest relative humidity is May (77%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Saint Charles, MO
- Average rainfall in December: 1.73"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is February (1.42").
Average rainfall days in December
Saint Charles, MO
- Average rainfall days in December: 7.3 days
The month with the highest number of rainy days is July (16.3 days).
The months with the least rainy days are February and December (7.3 days).
Average snowfall in December
Saint Charles, MO
- Average snowfall in December: 1.81"
The month with the highest snowfall is February (2.05").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Saint Charles, MO
- Average snowfall days in December: 4.4 days
The month with the highest number of snowfall days is January (6.8 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 Charles, MO
- Average daylight in December: 9h and 30min
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 54min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in December
Saint Charles, MO
- Average sunshine days in December: 18.8 days
The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is July (11.4 days).
Average UV index in December
Saint Charles, MO
- 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
Saint Charles, MO
- Average cloud cover in December: 48
The month with the most cloud cover is January (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in December
Saint Charles, MO
- 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).





