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 arrival of December corresponds with a temperature reduction, down from November's fresh 50°F (10°C) to a cold 40.1°F (4.5°C). Throughout December, the temperature in Williamstown falls to an average low of 29.3°F (-1.5°C).Humidity
January and December, with an average relative humidity of 82%, are the most humid months.Rainfall
In Williamstown, during December, the rain falls for 10.7 days and regularly aggregates up to 2.32" (59mm) of precipitation. Throughout the year, in Williamstown, there are 161.3 rainfall days, and 31.26" (794mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, October through December. In Williamstown, in December, snow falls for 7.8 days, with typically accumulated 1.77" (45mm) of snow. Throughout the year, there are 35 snowfall days, and 10.67" (271mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 24min of daylight.On the first day of the month, sunrise is at 7:43 am and sunset at 5:18 pm. On the last day of December, sunrise is at 8:01 am and sunset at 5:28 pm EST.
Sunshine
In December, the average sunshine is 4h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for average individuals.Note: In December, an average UV index of 1 transforms into the following instructions:
Children must always have sun protection, unlike most people, who can tolerate up to an hour in the sun without any burns. The Sun's most harmful UV rays are emitted around midday; avoid staying outdoors for long during this time. A hat with a broad brim is indispensable, filtering out up to half of UV rays. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
What are the most humid months?
What is the average humidity in December?
How many days does it rain in December?
How much does it snow in December?
What is the month with the shortest days in Williamstown?
How many hours of daylight does Williamstown have in December?
When is the sunrise / 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, IN
- Average high temperature in December: 40.1°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (34.7°F).
- Average low temperature in December: 29.3°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (21.9°F).
Average pressure in December
Williamstown, IN
- Average pressure in December: 30.12"Hg
The months with the highest atmospheric pressure are January and November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in December
Williamstown, IN
- Average wind speed in December: 8.9mph
The windiest month (with the highest average wind speed) is January (9.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.6mph).
Average humidity in December
Williamstown, IN
- Average humidity in December: 82%
The months with the highest relative humidity are January and December (82%).
The month with the lowest relative humidity is October (74%).
Average rainfall in December
Williamstown, IN
- Average rainfall in December: 2.32"
The wettest month (with the highest rainfall) is May (3.78").
The driest month (with the least rainfall) is September (1.97").
Average rainfall days in December
Williamstown, IN
- Average rainfall days in December: 10.7 days
The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is February (8.4 days).
Average snowfall in December
Williamstown, IN
- Average snowfall in December: 1.77"
The month with the highest snowfall is February (2.64").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Williamstown, IN
- Average snowfall days in December: 7.8 days
The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Williamstown, IN
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in December: 4h and 0min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in December
Williamstown, IN
- Average sunshine days in December: 13.8 days
The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is May (9.9 days).
Average UV index in December
Williamstown, IN
- Average UV index in December: 1
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Williamstown, IN
- Average cloud cover in December: 57
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in December
Williamstown, IN
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Williamstown, Indiana, USA
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