December weather forecastGarrison, IA
December
Weather in December
The first month of the winter, December, is also a wintry month in Garrison, Iowa, with an average temperature varying between 32.2°F (0.1°C) and 21.6°F (-5.8°C).Temperature
The arrival of December corresponds with a temperature reduction, down from November's frosty 45°F (7.2°C) to a wintry 32.2°F (0.1°C). Garrison, during the nights of December, experiences an average temperature drop to a subzero cold 21.6°F (-5.8°C).Humidity
The average relative humidity in December is 82%.Rainfall
In Garrison, in December, during 3.8 rainfall days, 0.43" (11mm) of precipitation is typically accumulated. In Garrison, during the entire year, the rain falls for 103.1 days and collects up to 10.63" (270mm) of precipitation.Snowfall
Months with snowfall in Garrison are January through April, October through December. In Garrison, during December, snow falls for 5.5 days and regularly aggregates up to 0.47" (12mm) of snow. Throughout the year, there are 29.1 snowfall days, and 4.92" (125mm) of snow is accumulated.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year in Garrison, Iowa.On the first day of the month, sunrise is at 7:18 am and sunset at 4:37 pm. On the last day of December, sunrise is at 7:36 am and sunset at 4:46 pm CST.
Sunshine
In Garrison, the average sunshine in December is 4.3h.UV index
With an average maximum UV index of 1, December is the month with the lowest UV index. A UV Index value of 2, and less, symbolizes a low threat to health from unsafe exposure to UV radiation for the average person.Note: A maximum high UV index of 1 in December translates into the following recommendations:
Most individuals can handle sun exposure for up to an hour without burning, but children must always be shielded from sun exposure. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Remember this! The UV radiation of the Sun can be nearly doubled by the reflective properties of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Garrison, IA
- Average high temperature in December: 32.2°F
The warmest month (with the highest average high temperature) is July (80.1°F).
The month with the lowest average high temperature is January (25.3°F).
- Average low temperature in December: 21.6°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (13.1°F).
Average pressure in December
Garrison, 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
Garrison, IA
- Average wind speed in December: 10mph
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 (7mph).
Average humidity in December
Garrison, IA
- Average humidity in December: 82%
The month with the highest relative humidity is January (86%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Garrison, IA
- Average rainfall in December: 0.43"
The wettest month (with the highest rainfall) is May (1.85").
The driest month (with the least rainfall) is February (0.39").
Average rainfall days in December
Garrison, IA
- Average rainfall days in December: 3.8 days
The month with the highest number of rainy days is June (13.9 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in December
Garrison, IA
- Average snowfall in December: 0.47"
The month with the highest snowfall is January (1.73").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Garrison, IA
- Average snowfall days in December: 5.5 days
The month with the highest number of snowfall days is February (7.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Garrison, IA
- Average daylight in December: 9h and 12min
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 12min).
- Average sunshine in December: 4h and 18min
The month with the most sunshine is July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in December
Garrison, IA
- Average sunshine days in December: 21.9 days
The month with the most sunshine days is December (21.9 days).
The month with the least sunshine days is June (13.4 days).
Average UV index in December
Garrison, IA
- Average UV index in December: 1
The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in December
Garrison, IA
- Average cloud cover in December: 55
The month with the most cloud cover is January (Cloud cover 59).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility in December
Garrison, IA
- 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).





