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 icy 41.4°F (5.2°C) to a freezing cold 27.3°F (-2.6°C). December nights in Grafton are marked by an average temperature drop to 16.5°F (-8.6°C).Humidity
The average relative humidity in December in Grafton is 87%.Rainfall
In Grafton, in December, it is raining for 5.5 days, with typically 1.3" (33mm) of accumulated precipitation. Throughout the year, there are 134.3 rainfall days, and 25.08" (637mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In Grafton, during December, snow falls for 12.6 days and regularly aggregates up to 3.66" (93mm) of snow. In Grafton, during the entire year, snow falls for 57 days and aggregates up to 22.83" (580mm) of snow.Daylight
December has the shortest days of the year, with an average of 9h and 0min of daylight.On the first day of December, sunrise is at 7:25 am and sunset at 4:37 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 4:46 pm CST.
Sunshine
In Grafton, the average sunshine in December is 3.9h.UV index
January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: A maximum UV index of 1 in December translates into the following recommendations:
Most people face no serious problems with extended sun exposure, but those with fair skin, infants, and children always need protection. Direct Sun exposure should be minimized especially during midday when radiation is most intense. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
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 much does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Grafton have in December?
When is the sunrise / sunset in December?
How many hours of sunshine does Grafton have in December?
What are the months with the lowest UV index?
How high is the UV index in December?
Average temperature in December
Grafton, IA
- Average high temperature in December: 27.3°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 (21.6°F).
- Average low temperature in December: 16.5°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 (9°F).
Average pressure in December
Grafton, IA
- Average pressure in December: 30.11"Hg
The months with the highest atmospheric pressure are January and February (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in December
Grafton, 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 (7.4mph).
Average humidity in December
Grafton, IA
- Average humidity in December: 87%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are April and October (72%).
Average rainfall in December
Grafton, IA
- Average rainfall in December: 1.3"
The wettest month (with the highest rainfall) is June (4.13").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in December
Grafton, IA
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is June (18.4 days).
The month with the least rainy days is February (2.9 days).
Average snowfall in December
Grafton, IA
- Average snowfall in December: 3.66"
The month with the highest snowfall is February (5.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Grafton, IA
- Average snowfall days in December: 12.6 days
The month with the highest number of snowfall days is January (13.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Grafton, IA
- Average daylight in December: 9h and 0min
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 0min).
- Average sunshine in December: 3h and 5min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in December
Grafton, IA
- Average sunshine days in December: 14.7 days
The month with the most sunshine days is October (18.1 days).
The month with the least sunshine days is June (9.1 days).
Average UV index in December
Grafton, IA
- Average UV index in December: 1
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).
Average cloud cover in December
Grafton, IA
- Average cloud cover in December: 61
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Grafton, IA
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, September, October and November (6mi).
The months with the lowest visibility are January, February, July, August and December (5mi).
Grafton, Iowa, USA
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