December weather forecastMystic, IA
December
Weather in December
December, the first month of the winter in Mystic, is also a wintry month, with an average temperature ranging between min 23.9°F (-4.5°C) and max 35.8°F (2.1°C).Temperature
Mystic's transition into December involves a shift in temperature, receding from a frosty 48.4°F (9.1°C) in November to a cold 35.8°F (2.1°C). An average minimum temperature of 23.9°F (-4.5°C) is recorded during the month of December.Humidity
In December, the average relative humidity is 79%.Rainfall
In Mystic, during December, the rain falls for 7 days and regularly aggregates up to 1.22" (31mm) of precipitation. In Mystic, during the entire year, the rain falls for 143.2 days and collects up to 27.48" (698mm) of precipitation.Snowfall
January through May, October through December are months with snowfall. In Mystic, during December, snow falls for 7.2 days and regularly aggregates up to 1.57" (40mm) of snow. In Mystic, during the entire year, snow falls for 33.2 days and aggregates up to 15.31" (389mm) of snow.Daylight
The month with the shortest days in Mystic is December, with an average of 9h and 18min of daylight.On the first day of December, sunrise is at 7:17 am and sunset at 4:44 pm. On the last day of the month, sunrise is at 7:35 am and sunset at 4:54 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 reading of 2, and below, represents a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index, 2 during December, leads to the following recommendations:
Children, babies, and those with sensitive skin should always be shielded from long periods of sun exposure. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Be aware! The reflective nature of snow can magnify the Sun's UV radiation almost twofold.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in December
Mystic, IA
- Average high temperature in December: 35.8°F
The warmest month (with the highest average high temperature) is July (83.1°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in December: 23.9°F
The month with the highest average low temperature is July (66°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in December
Mystic, 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
Mystic, IA
- Average wind speed in December: 10.1mph
The windiest months (with the highest average wind speed) are January, February and March (10.6mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in December
Mystic, IA
- Average humidity in December: 79%
The month with the highest relative humidity is June (83%).
The month with the lowest relative humidity is October (72%).
Average rainfall in December
Mystic, IA
- Average rainfall in December: 1.22"
The wettest month (with the highest rainfall) is June (3.98").
The driest month (with the least rainfall) is January (1.02").
Average rainfall days in December
Mystic, IA
- Average rainfall days in December: 7 days
The month with the highest number of rainy days is May (18.2 days).
The month with the least rainy days is January (5 days).
Average snowfall in December
Mystic, IA
- Average snowfall in December: 1.57"
The month with the highest snowfall is January (4.33").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Mystic, IA
- Average snowfall days in December: 7.2 days
The month with the highest number of snowfall days is January (9.4 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Mystic, IA
- Average daylight in December: 9h and 18min
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 18min).
- Average sunshine in December: 4h and 48min
The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is January (Average sunshine: 4h and 18min).
Average sunshine days in December
Mystic, IA
- Average sunshine days in December: 18.1 days
The month with the most sunshine days is November (18.6 days).
The month with the least sunshine days is June (8.8 days).
Average UV index in December
Mystic, IA
- Average UV index in December: 2
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in December
Mystic, IA
- Average cloud cover in December: 48
The month with the most cloud cover is January (Cloud cover 53).
The months with the least cloud cover are July, August and September (Cloud cover 29).
Average visibility in December
Mystic, IA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





