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 arrives, Sumner's weather displays a decrease in high-temperatures, transitioning from November's frosty 43°F (6.1°C) to a subzero cold 29.8°F (-1.2°C). The mean low-temperature during December nights is 19.4°F (-7°C).Humidity
In Sumner, the average relative humidity in December is 84%.Rainfall
In Sumner, during December, the rain falls for 6.4 days and regularly aggregates up to 1.61" (41mm) of precipitation. Throughout the year, there are 146.8 rainfall days, and 30.79" (782mm) of precipitation is accumulated.Snowfall
January through May, October through December are months with snowfall. In December, in Sumner, it is snowing for 12.5 days. Throughout December, 4.61" (117mm) of snow is accumulated. In Sumner, during the entire year, snow falls for 55.9 days and aggregates up to 23.46" (596mm) of snow.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 7:20 am and sunset at 4:35 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:44 pm CST.
Sunshine
The average sunshine in December is 4.1h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index of 2, and less, symbolizes a minimal health vulnerability from exposure to the Sun's UV rays for average individuals.Note: The daily maximum UV index of 1 in December interprets into the following advice:
Unlike children, who always need sun protection, most individuals can remain in the sun for up to an hour without getting burnt. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Tightly woven clothing, when worn loosely, shields effectively against the Sun. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
How cold is it in December?
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?
How many hours of daylight does Sumner have in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Sumner have in December?
When is the lowest UV index?
How high is the UV index in December?
Average temperature in December
Sumner, IA
- Average high temperature in December: 29.8°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (23.5°F).
- Average low temperature in December: 19.4°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (11.1°F).
Average pressure in December
Sumner, IA
- Average pressure in December: 30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in December
Sumner, IA
- Average wind speed in December: 10.1mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).
Average humidity in December
Sumner, IA
- Average humidity in December: 84%
The months with the highest relative humidity are January and February (88%).
The month with the lowest relative humidity is October (73%).
Average rainfall in December
Sumner, IA
- Average rainfall in December: 1.61"
The wettest month (with the highest rainfall) is June (5.04").
The driest month (with the least rainfall) is January (1.14").
Average rainfall days in December
Sumner, IA
- Average rainfall days in December: 6.4 days
The month with the highest number of rainy days is May (20.3 days).
The months with the least rainy days are January and February (4.3 days).
Average snowfall in December
Sumner, IA
- Average snowfall in December: 4.61"
The month with the highest snowfall is February (5.83").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Sumner, IA
- Average snowfall days in December: 12.5 days
The month with the highest number of snowfall days is January (13.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Sumner, IA
- Average daylight in December: 9h and 1min
The month with the longest days is June (Average daylight: 15h and 18min).
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 48min).
The month with the least sunshine is January (Average sunshine: 3h and 36min).
Average sunshine days in December
Sumner, IA
- Average sunshine days in December: 15.5 days
The month with the most sunshine days is November (16.8 days).
The month with the least sunshine days is June (7.3 days).
Average UV index in December
Sumner, IA
- Average UV index in December: 1
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in December
Sumner, IA
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are August and September (Cloud cover 32).
Average visibility in December
Sumner, IA
- Average visibility in December: 6mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
Sumner, Iowa, USA
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