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
Williams experiences a temperature shift at the start of December, with average high-temperatures adjusting from a frosty 43.9°F (6.6°C) in November to a freezing cold 30.7°F (-0.7°C). Williams's nighttime temperature in December drops to an average of 19.9°F (-6.7°C).Humidity
In Williams, the average relative humidity in December is 83%.Rainfall
In December, the rain falls for 5.1 days. Throughout December, 1.26" (32mm) of precipitation is accumulated. In Williams, during the entire year, the rain falls for 132 days and collects up to 27.01" (686mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In Williams, in December, snow falls for 10.5 days, with typically accumulated 2.87" (73mm) of snow. Throughout the year, there are 44.4 snowfall days, and 16.65" (423mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 6min of daylight.On the first day of December, sunrise is at 7:24 am and sunset at 4:42 pm. On the last day of the month, sunrise is at 7:43 am and sunset at 4:51 pm CST.
Sunshine
In December, the average sunshine is 4.2h.UV index
January, February, October through December, with an average maximum UV index of 2, are months with the lowest UV index in Williams. A UV Index reading of 2, and below, represents a low health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 2 during December translates into these guidelines:
Extended time in the sun generally does not harm most, but those with sensitive skin, infants, and children should always be protected. Exposing oneself to the midday Sun can be harmful due to the strong UV radiation; limit your time outside. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is December?
What is the average humidity in December?
How many days does it rain in December?
How many days does it snow in December?
What is the month with the shortest days in Williams?
How many hours of daylight does Williams have in December?
When is the sunrise / sunset in December in Williams?
How many hours of sunshine does Williams have in December?
When is the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Williams, IA
- Average high temperature in December: 30.7°F
The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (24.3°F).
- Average low temperature in December: 19.9°F
The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (11.8°F).
Average pressure in December
Williams, IA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Williams, IA
- Average wind speed in December: 10.4mph
The windiest month (with the highest average wind speed) is April (11.1mph).
The calmest months (with the lowest average wind speed) are July and August (7.3mph).
Average humidity in December
Williams, IA
- Average humidity in December: 83%
The month with the highest relative humidity is January (87%).
The month with the lowest relative humidity is October (70%).
Average rainfall in December
Williams, IA
- Average rainfall in December: 1.26"
The wettest month (with the highest rainfall) is June (4.06").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in December
Williams, IA
- Average rainfall days in December: 5.1 days
The month with the highest number of rainy days is June (17.9 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in December
Williams, IA
- Average snowfall in December: 2.87"
The month with the highest snowfall is January (4.17").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Williams, IA
- Average snowfall days in December: 10.5 days
The month with the highest number of snowfall days is January (11.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Williams, IA
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in December: 4h and 1min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in December
Williams, IA
- Average sunshine days in December: 17.5 days
The month with the most sunshine days is November (18.1 days).
The month with the least sunshine days is June (10.4 days).
Average UV index in December
Williams, IA
- Average UV index in December: 2
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in December
Williams, IA
- Average cloud cover in December: 56
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility in December
Williams, IA
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Williams, Iowa, USA
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