December weather forecastSwan, IA
December
Weather in December
December, the first month of the winter in Swan, is also a wintry month, with an average temperature varying between 22.8°F (-5.1°C) and 34.3°F (1.3°C).Temperature
December implies a gentle temperature shift, with average high-temperatures reducing from November's frosty 47.1°F (8.4°C) to a cold 34.3°F (1.3°C). December witnesses an average nighttime temperature of 22.8°F (-5.1°C) in Swan.Humidity
The average relative humidity in December in Swan is 79%.Rainfall
January and December are months with the least rain when the rain falls for 4.5 days and typically aggregates up to 0.39" (10mm) of rain.Snowfall
Months with snowfall are January through April, October through December. In Swan, in December, during 5.1 snowfall days, 0.55" (14mm) of snow is typically accumulated. Throughout the year, there are 28.4 snowfall days, and 5.71" (145mm) of snow is accumulated.Daylight
With an average of 9h and 12min of daylight, December has the shortest days of the year.On the first day of December in Swan, Iowa, sunrise is at 7:20 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:39 am and sunset at 4:53 pm CST.
Sunshine
In December, the average sunshine is 4.8h.UV index
In December, the average daily maximum UV index is 2. A UV Index value of 2, and less, symbolizes a low health risk from exposure to the Sun's UV rays for the average person.Note: The UV index of 2 in December translates into these instructions:
Long-term sun exposure is typically not a concern for most. However, those with sensitive skin, infants, and children must always have protection. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Enhance your sun protection with tightly woven, yet airy clothing. Consider carefully! The reflective quality of snow 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
Average temperature in December
Swan, IA
- Average high temperature in December: 34.3°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (28.4°F).
- Average low temperature in December: 22.8°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (15.1°F).
Average pressure in December
Swan, IA
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in December
Swan, IA
- Average wind speed in December: 9.9mph
The windiest months (with the highest average wind speed) are January and April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.8mph).
Average humidity in December
Swan, IA
- Average humidity in December: 79%
The month with the highest relative humidity is January (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Swan, IA
- Average rainfall in December: 0.39"
The wettest month (with the highest rainfall) is May (2.28").
The driest months (with the least rainfall) are January and December (0.39").
Average rainfall days in December
Swan, IA
- Average rainfall days in December: 4.5 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is February (3.3 days).
Average snowfall in December
Swan, IA
- Average snowfall in December: 0.55"
The month with the highest snowfall is January (1.97").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in December
Swan, IA
- Average snowfall days in December: 5.1 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Swan, IA
- Average daylight in December: 9h and 12min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in December: 4h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in December
Swan, IA
- Average sunshine days in December: 22.7 days
The month with the most sunshine days is December (22.7 days).
The month with the least sunshine days is June (10.9 days).
Average UV index in December
Swan, IA
- Average UV index in December: 2
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Swan, IA
- Average cloud cover in December: 50
The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July, August and September (Cloud cover 29).
Average visibility in December
Swan, IA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
