Contents
- Weather in December
- Frequently asked questions
- Average temperature in December
- Average pressure in December
- Average wind speed in December
- Average humidity in December
- Average rainfall in December
- Average rainfall days in December
- Average snowfall in December
- Average snowfall days in December
- Average daylight in December
- Average sunshine in December
- Average sunshine days in December
- Average UV index in December
- Average cloud cover in December
- Average visibility in December
Weather in December
Temperature
In December, the average high-temperature decreases from a frosty 47.5°F (8.6°C) in November to an icy 34.7°F (1.5°C). Saint Marys experiences a nighttime temperature average of 22.8°F (-5.1°C) during December.Humidity
In December, the average relative humidity is 78%.Rainfall
The month with the least rainfall is December, when the rain falls for 4.7 days and typically collects 0.55" (14mm) of precipitation.Snowfall
Months with snowfall are January through May, October through December. In December, in Saint Marys, it is snowing for 5.7 days. Throughout December, 0.94" (24mm) of snow is accumulated. In Saint Marys, during the entire year, snow falls for 31.9 days and aggregates up to 10.12" (257mm) of snow.Daylight
With an average of 9h and 18min of daylight, December has the shortest days of the year.On the first day of December, sunrise is at 7:22 am and sunset at 4:46 pm. On the last day of the month, sunrise is at 7:40 am and sunset at 4:55 pm CST.
Sunshine
In Saint Marys, the average sunshine in December is 4.8h.UV index
In Saint Marys, Iowa, the average daily maximum UV index in December is 2. A UV Index of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.Note: A daily maximum UV index of 2 in December translates into the following instructions:
Children, infants, and individuals with sensitive skin should be constantly protected from extended sun exposure. When the Sun is at its strongest around midday, find shade and limit exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Take to heart! Snow reflection can almost magnify the Sun's UV radiation twofold.
Frequently asked questions
How cold is it in Saint Marys in December?
What is the average humidity in December in Saint Marys?
What is the driest month in Saint Marys?
How much does it rain in Saint Marys in December?
How many days does it snow in December in Saint Marys?
What is the month with the shortest days in Saint Marys?
What is the average length of the day in December in Saint Marys?
When is the sunrise / sunset in December in Saint Marys?
How long on average sun shines in December in Saint Marys?
What is the UV index intensity in December in Saint Marys?
Average temperature in December
Saint Marys, IA
- Average high temperature in December: 34.7°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 (28.8°F).
- Average low temperature in December: 22.8°F
The month with the highest average low temperature is July (65.7°F).
The coldest month (with the lowest average low temperature) is January (15.3°F).
Average pressure in December
Saint Marys, 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
Saint Marys, IA
- Average wind speed in December: 9.9mph
The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).
Average humidity in December
Saint Marys, IA
- Average humidity in December: 78%
The months with the highest relative humidity are January and June (82%).
The month with the lowest relative humidity is October (71%).
Average rainfall in December
Saint Marys, IA
- Average rainfall in December: 0.55"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is December (0.55").
Average rainfall days in December
Saint Marys, IA
- Average rainfall days in December: 4.7 days
The months with the highest number of rainy days are May and June (15.9 days).
The month with the least rainy days is January (3.4 days).
Average snowfall in December
Saint Marys, IA
- Average snowfall in December: 0.94"
The month with the highest snowfall is February (3.03").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in December
Saint Marys, IA
- Average snowfall days in December: 5.7 days
The month with the highest number of snowfall days is January (9.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in December /
Average sunshine in December
Saint Marys, IA
- Average daylight in December: 9h and 2min
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 5min
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
Saint Marys, 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 (11 days).
Average UV index in December
Saint Marys, 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
Saint Marys, IA
- Average cloud cover in December: 49
The month with the most cloud cover is January (Cloud cover 53).
The month with the least cloud cover is July (Cloud cover 28).
Average visibility in December
Saint Marys, 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).
Saint Marys, Iowa, USA
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