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
As December commences, the average high-temperature shows a reduction, transitioning from a chilly 48°F (8.9°C) in November to a wintry 34.9°F (1.6°C). In the month of December, an average of 23.2°F (-4.9°C) marks the low-temperature.Humidity
In December, the average relative humidity is 79%.Rainfall
In December, the rain falls for 6.1 days. Throughout December, 1.06" (27mm) of precipitation is accumulated. Throughout the year, in Williamson, there are 131.1 rainfall days, and 25.71" (653mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In Williamson, Iowa, during December, snow falls for 6.4 days and regularly aggregates up to 1.54" (39mm) of snow. In Williamson, during the entire year, snow falls for 33.4 days and aggregates up to 13.54" (344mm) of snow.Daylight
The month with the shortest days in Williamson is December, with an average of 9h and 18min of daylight.On the first day of December in Williamson, Iowa, sunrise is at 7:19 am and sunset at 4:45 pm. On the last day of the month, sunrise is at 7:38 am and sunset at 4:54 pm CST.
Sunshine
The average sunshine in December is 4.6h.UV index
The average daily maximum UV index in December in Williamson, Iowa, is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.Note: The daily high UV index of 2 during December translates into the following recommendations:
Most people can stay in the Sun for up to 1 hour without burning, apart from children that always must be protected from sun exposure. The solar radiation around mid-day is intense; avoid the Sun and stay safe. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Take precaution! The reflection from snow can almost double the UV radiation of the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in Williamson in December?
What is the average humidity in December in Williamson?
How many days does it rain in December in Williamson?
How many days does it snow in December in Williamson?
What is the month with the shortest days in Williamson?
What is the average length of the day in December in Williamson?
What time are sunrise and sunset in December in Williamson?
How many hours of sunshine does Williamson have in December?
What is the UV index reading in December in Williamson?
Average temperature in December
Williamson, IA
- Average high temperature in December: 34.9°F
The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (29.3°F).
- Average low temperature in December: 23.2°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (16°F).
Average pressure in December
Williamson, IA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in December
Williamson, IA
- Average wind speed in December: 10.3mph
The windiest month (with the highest average wind speed) is January (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).
Average humidity in December
Williamson, IA
- Average humidity in December: 79%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Williamson, IA
- Average rainfall in December: 1.06"
The wettest month (with the highest rainfall) is June (3.74").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in December
Williamson, IA
- Average rainfall days in December: 6.1 days
The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is January (4.7 days).
Average snowfall in December
Williamson, IA
- Average snowfall in December: 1.54"
The month with the highest snowfall is February (4.13").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Williamson, IA
- Average snowfall days in December: 6.4 days
The month with the highest number of snowfall days is January (10.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Williamson, IA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in December: 4h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Williamson, IA
- Average sunshine days in December: 19.1 days
The month with the most sunshine days is November (19.3 days).
The month with the least sunshine days is June (10.7 days).
Average UV index in December
Williamson, IA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Williamson, IA
- Average cloud cover in December: 50
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and August (Cloud cover 30).
Average visibility in December
Williamson, IA
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, July, September, October, November and December (6mi).
The months with the lowest visibility are January and August (5mi).
Williamson, Iowa, USA
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