December weather forecastPlymouth, IA
December
Weather in December
The first month of the winter, December, is also a subzero cold month in Plymouth, Iowa, with an average temperature fluctuating between 18°F (-7.8°C) and 28.4°F (-2°C).Temperature
December's onset brings a clear reduction in the average high-temperature, falling from a chilly 42.8°F (6°C) in November to a freezing cold 28.4°F (-2°C). During the month of December, the temperature falls to an average of 18°F (-7.8°C).Humidity
In Plymouth, the average relative humidity in December is 85%.Rainfall
In December, the rain falls for 5.5 days. Throughout December, 1.34" (34mm) of precipitation is accumulated. In Plymouth, during the entire year, the rain falls for 129.5 days and collects up to 25.98" (660mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Plymouth, in December, during 11.7 snowfall days, 3.35" (85mm) of snow is typically accumulated. Throughout the year, there are 50.1 snowfall days, and 21.69" (551mm) of snow is accumulated.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 4:38 pm. On the last day of the month, sunrise is at 7:44 am and sunset at 4:47 pm CST.
Sunshine
In Plymouth, the average sunshine in December is 4.2h.UV index
The months with the lowest UV index are January and December, with an average maximum UV index of 1. A UV Index value of 2, and less, symbolizes a low threat to health from exposure to the Sun's UV radiation for the ordinary person.Note: In December, the UV index of 1 transforms into the following advice:
While many people can endure lengthy sun exposure, it remains imperative to safeguard babies, children, and fair-skinned individuals. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Limit sun-induced ocular harm with sunglasses that feature UVA and UVB filtration. 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
Plymouth, IA
- Average high temperature in December: 28.4°F
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (22.5°F).
- Average low temperature in December: 18°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 (10°F).
Average pressure in December
Plymouth, 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
Plymouth, IA
- Average wind speed in December: 10.1mph
The windiest months (with the highest average wind speed) are January and April (10.7mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in December
Plymouth, IA
- Average humidity in December: 85%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Plymouth, IA
- Average rainfall in December: 1.34"
The wettest month (with the highest rainfall) is June (3.98").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in December
Plymouth, IA
- Average rainfall days in December: 5.5 days
The month with the highest number of rainy days is June (17.8 days).
The month with the least rainy days is February (3 days).
Average snowfall in December
Plymouth, IA
- Average snowfall in December: 3.35"
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
Plymouth, IA
- Average snowfall days in December: 11.7 days
The month with the highest number of snowfall days is January (12.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Plymouth, 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: 4h and 12min
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 36min).
Average sunshine days in December
Plymouth, IA
- Average sunshine days in December: 16.4 days
The month with the most sunshine days is November (17.7 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in December
Plymouth, 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 and December (UV index 1).
Average cloud cover in December
Plymouth, IA
- Average cloud cover in December: 58
The month with the most cloud cover is January (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Plymouth, IA
- Average visibility in December: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).





