December weather forecastMason City, IA
December
Weather in December
As the final month of the year, December in Mason City is a blend of holiday cheer and winter fury. Temperatures plunge as the winter season settles in, making warm clothing an absolute necessity. The reduced daylight hours juxtapose with the festive lights illuminating the city, adding to the holiday spirit. Snowfall intensifies, transforming the city into a mesmerizing winter wonderland while the increased humidity solidifies the frosty winter ambience. As the year concludes, this chilled month marks the full return of winter, closing the climatic circle, ready to begin afresh with the New Year.Temperature
Mason City experiences a clear temperature downturn in December, with average high-temperatures moving from a cold 42.6°F (5.9°C) in November to a freezing cold 28.2°F (-2.1°C). In Mason City, the average nighttime temperature during December is 17.8°F (-7.9°C).Humidity
The average relative humidity in December is 86%.Rainfall
In December, the rain falls for 5.8 days. Throughout December, 1.57" (40mm) of precipitation is accumulated. Throughout the year, there are 145.9 rainfall days, and 28.82" (732mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. In December, it is snowing for 13.3 days. Throughout December, 4.17" (106mm) of snow is accumulated. Throughout the year, there are 60.2 snowfall days, and 26.26" (667mm) of snow is accumulated.Daylight
With an average of 9h and 6min of daylight, December has the shortest days of the year.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 Mason City, the average sunshine in December is 4.1h.UV index
January and December, with an average maximum UV index of 1, are months with the lowest UV index. A UV Index of 2, and less, symbolizes a low health risk from unsafe exposure to UV radiation for the average person.Note: In December, the average maximum UV index of 1 translates into the following recommendations:
Babies, children, and individuals with sensitive skin should always have protection against extended sun exposure. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Observe! Snow reflection can nearly intensify the Sun's UV radiation twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mason City, IA
- Average high temperature in December: 28.2°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 (22.3°F).
- Average low temperature in December: 17.8°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 (9.9°F).
Average pressure in December
Mason City, 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
Mason City, IA
- Average wind speed in December: 10.4mph
The windiest months (with the highest average wind speed) are January and April (10.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.3mph).
Average humidity in December
Mason City, IA
- Average humidity in December: 86%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Mason City, IA
- Average rainfall in December: 1.57"
The wettest month (with the highest rainfall) is June (4.65").
The driest month (with the least rainfall) is January (1.06").
Average rainfall days in December
Mason City, IA
- Average rainfall days in December: 5.8 days
The month with the highest number of rainy days is June (19.8 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in December
Mason City, IA
- Average snowfall in December: 4.17"
The month with the highest snowfall is February (7.48").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Mason City, IA
- Average snowfall days in December: 13.3 days
The month with the highest number of snowfall days is January (14.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mason City, IA
- Average daylight in December: 9h and 6min
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 6min
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 30min).
Average sunshine days in December
Mason City, IA
- Average sunshine days in December: 14.5 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (8 days).
Average UV index in December
Mason City, 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
Mason City, IA
- Average cloud cover in December: 59
The month with the most cloud cover is January (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in December
Mason City, IA
- Average visibility in December: 5mi
The months with the highest visibility are March, April, May, June, August, September, October and November (6mi).
The months with the lowest visibility are January, February, July and December (5mi).
