December weather forecastArnold, MO
December
Weather in December
December, the first month of the winter in Arnold, is still a chilly month, with an average temperature fluctuating between 30.7°F (-0.7°C) and 43.2°F (6.2°C).Temperature
December's arrival corresponds with a decrease in average high-temperatures, from November's fresh 53.8°F (12.1°C) to a frosty 43.2°F (6.2°C). During December, the average low-temperature is recorded at a subzero cold 30.7°F (-0.7°C).Humidity
In December, the average relative humidity is 76%.Rainfall
In Arnold, in December, during 8.2 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. In Arnold, during the entire year, the rain falls for 146.1 days and collects up to 32.36" (822mm) of precipitation.Snowfall
January through March, November and December are months with snowfall. In Arnold, in December, during 3 snowfall days, 1.89" (48mm) of snow is typically accumulated. Throughout the year, there are 15.3 snowfall days, and 8.27" (210mm) 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 in Arnold, sunrise is at 7:00 am and sunset at 4:41 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:51 pm CST.
Sunshine
The average sunshine in December 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 value of 2, and less, symbolizes a minimal health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: In December, the average maximum UV index of 2 translates into the following recommendations:
Although the majority can endure up to an hour in the sun without burns, children always require sun protection. The midday Sun can be dangerous due to its intense radiation; always find shade and reduce exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Arnold, MO
- Average high temperature in December: 43.2°F
The warmest month (with the highest average high temperature) is July (86.9°F).
The month with the lowest average high temperature is January (37.9°F).
- Average low temperature in December: 30.7°F
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (25°F).
Average pressure in December
Arnold, 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
Arnold, MO
- Average wind speed in December: 8.5mph
The windiest month (with the highest average wind speed) is January (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).
Average humidity in December
Arnold, MO
- Average humidity in December: 76%
The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Arnold, MO
- Average rainfall in December: 2.2"
The wettest month (with the highest rainfall) is May (3.94").
The driest months (with the least rainfall) are February and November (1.77").
Average rainfall days in December
Arnold, MO
- Average rainfall days in December: 8.2 days
The month with the highest number of rainy days is July (16.9 days).
The months with the least rainy days are January and February (6.8 days).
Average snowfall in December
Arnold, MO
- Average snowfall in December: 1.89"
The month with the highest snowfall is February (2.6").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Arnold, MO
- Average snowfall days in December: 3 days
The months with the highest number of snowfall days are January and February (4.8 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
Arnold, 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 June (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in December
Arnold, MO
- Average sunshine days in December: 19.7 days
The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is June (11.6 days).
Average UV index in December
Arnold, 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
Arnold, MO
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 28).
Average visibility in December
Arnold, 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).





