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
The shift to December brings a decrease in the average high-temperature, falling from a chilly 49.5°F (9.7°C) in November to a cold 37.6°F (3.1°C). In Williamstown, an average low-temperature of 25.7°F (-3.5°C) is recorded during December nights.Humidity
In Williamstown, the average relative humidity in December is 78%.Rainfall
In Williamstown, in December, it is raining for 6.1 days, with typically 1.3" (33mm) of accumulated precipitation. Throughout the year, there are 134.4 rainfall days, and 27.44" (697mm) of precipitation is accumulated.Snowfall
January through April, October through December are months with snowfall. In December, it is snowing for 5.1 days. Throughout December, 1.65" (42mm) of snow is accumulated. In Williamstown, during the entire year, snow falls for 24.7 days and aggregates up to 11.69" (297mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 24min of daylight.On the first day of December, sunrise is at 7:11 am and sunset at 4:41 pm. On the last day of the month, sunrise is at 7:29 am and sunset at 4:51 pm CST.
Sunshine
In Williamstown, the average sunshine in December is 4.8h.UV index
January, February, November 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 the average person.Note: A maximum UV index of 2 in December translates into the following recommendations:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What is the average humidity in December?
How many days does it rain in December in Williamstown?
How many days does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Williamstown have 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 reading in December?
Average temperature in December
Williamstown, MO
- Average high temperature in December: 37.6°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (31.6°F).
- Average low temperature in December: 25.7°F
The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in December
Williamstown, MO
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in December
Williamstown, MO
- Average wind speed in December: 9.9mph
The windiest month (with the highest average wind speed) is January (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (6.7mph).
Average humidity in December
Williamstown, MO
- Average humidity in December: 78%
The months with the highest relative humidity are June and July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Williamstown, MO
- Average rainfall in December: 1.3"
The wettest month (with the highest rainfall) is May (3.7").
The driest month (with the least rainfall) is January (1.22").
Average rainfall days in December
Williamstown, MO
- Average rainfall days in December: 6.1 days
The month with the highest number of rainy days is May (17.6 days).
The month with the least rainy days is February (4.7 days).
Average snowfall in December
Williamstown, MO
- Average snowfall in December: 1.65"
The month with the highest snowfall is January (3.98").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Williamstown, MO
- Average snowfall days in December: 5.1 days
The month with the highest number of snowfall days is January (7.4 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
Williamstown, MO
- Average daylight in December: 9h and 2min
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 24min).
- Average sunshine in December: 4h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in December
Williamstown, MO
- Average sunshine days in December: 19.5 days
The month with the most sunshine days is December (19.5 days).
The month with the least sunshine days is June (10.9 days).
Average UV index in December
Williamstown, MO
- 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
Williamstown, MO
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in December
Williamstown, 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).
Williamstown, Missouri, USA
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