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
December's onset brings a slight change in high-temperatures, falling from a fresh 51.1°F (10.6°C) in November to a cold 41.9°F (5.5°C). Marietta's average low-temperature is measured at a subzero cold 30°F (-1.1°C) during December.Humidity
In December, the average relative humidity is 79%.Rainfall
In Marietta, during December, the rain falls for 9.3 days and regularly aggregates up to 1.14" (29mm) of precipitation. Throughout the year, there are 130.2 rainfall days, and 16.22" (412mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through April, November and December. In Marietta, in December, snow falls for 3 days, with typically accumulated 0.71" (18mm) of snow. Throughout the year, there are 18.9 snowfall days, and 6.1" (155mm) of snow is accumulated.Daylight
With an average of 9h and 24min of daylight, December has the shortest days of the year.On the first day of the month, sunrise is at 7:09 am and sunset at 4:41 pm. On the last day of December, in Marietta, sunrise is at 7:28 am and sunset at 4:50 pm EST.
Sunshine
In December, the average sunshine in Marietta is 4.8h.UV index
January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index. A UV Index reading of 2, and below, represents a minimal health hazard from unprotected exposure to Sun's UV rays for the average person.Note: The maximum UV index of 2 during December leads to these instructions:
Despite most people tolerating extended sun exposure, it is critical to always protect those with sensitive skin, infants, and children. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Pay attention! The reflection of snow can enhance the Sun's UV radiation almost double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it cold during December?
What is the average humidity in December?
How much does it rain in December?
How many days does it snow in December?
What is the month with the shortest days?
What is the average length of the day in December?
What time are sunrise and sunset in December?
How many hours of sunshine does Marietta have in December?
What is the month with the lowest UV index?
What is the UV index intensity in December in Marietta?
Average temperature in December
Marietta, PA
- Average high temperature in December: 41.9°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 (35.4°F).
- Average low temperature in December: 30°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).
Average pressure in December
Marietta, PA
- Average pressure in December: 30.1"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in December
Marietta, PA
- Average wind speed in December: 8.3mph
The windiest months (with the highest average wind speed) are February and March (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).
Average humidity in December
Marietta, PA
- Average humidity in December: 79%
The month with the highest relative humidity is May (81%).
The months with the lowest relative humidity are March and April (76%).
Average rainfall in December
Marietta, PA
- Average rainfall in December: 1.14"
The wettest month (with the highest rainfall) is August (1.89").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in December
Marietta, PA
- Average rainfall days in December: 9.3 days
The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in December
Marietta, PA
- Average snowfall in December: 0.71"
The month with the highest snowfall is January (1.89").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in December
Marietta, PA
- Average snowfall days in December: 3 days
The month with the highest number of snowfall days is January (6.5 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Marietta, PA
- Average daylight in December: 9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- 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 February (Average sunshine: 4h and 30min).
Average sunshine days in December
Marietta, PA
- Average sunshine days in December: 18.5 days
The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is May (13.2 days).
Average UV index in December
Marietta, PA
- Average UV index in December: 2
The months with the highest UV index are May, June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in December
Marietta, PA
- Average cloud cover in December: 49
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in December
Marietta, PA
- Average visibility in December: 6mi
The months with the highest visibility are January, February, March, April, June, July, October, November and December (6mi).
The months with the lowest visibility are May, August and September (5mi).
Marietta, Pennsylvania, USA
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