Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
December brings a minor decrease, with the average high-temperature reducing from a cool 53.8°F (12.1°C) in November to a frosty 43.2°F (6.2°C). Affton records a consistent low-temperature of 30.7°F (-0.7°C) during December nights.Humidity
In Affton, the average relative humidity in December is 76%.Rainfall
In December, the rain falls for 8.2 days. Throughout December, 2.2" (56mm) of precipitation is accumulated. In Affton, during the entire year, the rain falls for 146.1 days and collects up to 32.36" (822mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In Affton, in December, snow falls for 3 days, with typically accumulated 1.89" (48mm) of snow. Throughout the year, there are 15.3 snowfall days, and 8.27" (210mm) of snow is accumulated.Daylight
December has the shortest days of the year, with an average of 9h and 30min of daylight.On the first day of December, sunrise is at 7:00 am and sunset at 4:40 pm. On the last day of the month, sunrise is at 7:18 am and sunset at 4:50 pm CST.
Sunshine
In Affton, the average sunshine in December is 4.9h.UV index
The months with the lowest UV index are January, February and December, with an average maximum UV index of 2. A UV Index reading of 2, and below, represents a low threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The UV index of 2 in December translates into these instructions:
The majority are not significantly affected by prolonged sun exposure. Infants, children, and those with fair skin must always have protection. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. Experience reduced UV exposure by about half when donning a wide-brim hat. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is December cold?
What is the average humidity in December in Affton?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
When are sunrise and sunset in December?
How long on average sun shines in December?
When is the lowest UV index?
What is the UV index intensity in December?
Average temperature in December
Affton, 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
Affton, 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
Affton, 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
Affton, 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
Affton, 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
Affton, 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
Affton, 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
Affton, 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
Affton, MO
- Average daylight in December: 9h and 3min
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 5min
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
Affton, 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
Affton, 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
Affton, 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
Affton, 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).
Affton, Missouri, USA
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