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 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
The advent of December reveals an average high-temperature of a still enjoyable 61°F (16.1°C), showing minimal difference from the prior month. In the month of December, the nighttime temperature dips to a steady average of 50.4°F (10.2°C).Humidity
December is the most humid month, with an average relative humidity of 78%.Rainfall
In Sullivan's Island, in December, during 10.5 rainfall days, 4.29" (109mm) of precipitation is typically accumulated. Throughout the year, there are 182 rainfall days, and 45.55" (1157mm) of precipitation is accumulated.Snowfall
In Sullivan's Island, snow does not fall in March through December.Daylight
December has the shortest days of the year, with an average of 10h and 0min of daylight.On the first day of the month, sunrise is at 7:04 am and sunset at 5:13 pm. On the last day of December, sunrise is at 7:21 am and sunset at 5:23 pm EST.
Sunshine
The month with the least sunshine is December, with an average of 5.7h of sunshine.UV index
The average daily maximum UV index in December is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: During December, 4 as the daily maximum UV index converts into the following advice:
Exercise prevention - Warding off sunburn is urged. To protect against the Sun's most potent rays, avoid direct exposure around midday. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are December temperatures?
What is the most humid month?
What is the average humidity in December?
How many days does it rain in December?
When it does not snow?
Does it snow in December?
What is the month with the shortest days?
How many hours of daylight does Sullivan's Island have in December?
What time are sunrise and sunset in December?
What is the month with the least sunshine in Sullivan's Island?
How many hours of sunshine does Sullivan's Island have in December?
What is the UV index reading in December?
Average temperature in December
Sullivan's Island, SC
- Average high temperature in December: 61°F
The warmest month (with the highest average high temperature) is July (86.5°F).
The month with the lowest average high temperature is January (57°F).
- Average low temperature in December: 50.4°F
The month with the highest average low temperature is July (78.3°F).
The coldest month (with the lowest average low temperature) is January (45.5°F).
Average pressure in December
Sullivan's Island, SC
- Average pressure in December: 30.12"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.98"Hg).
Average wind speed in December
Sullivan's Island, SC
- Average wind speed in December: 9.8mph
The windiest months (with the highest average wind speed) are March and April (10.3mph).
The calmest month (with the lowest average wind speed) is August (8.4mph).
Average humidity in December
Sullivan's Island, SC
- Average humidity in December: 78%
The month with the highest relative humidity is December (78%).
The months with the lowest relative humidity are January and March (73%).
Average rainfall in December
Sullivan's Island, SC
- Average rainfall in December: 4.29"
The wettest month (with the highest rainfall) is August (8.23").
The driest month (with the least rainfall) is January (1.42").
Average rainfall days in December
Sullivan's Island, SC
- Average rainfall days in December: 10.5 days
The month with the highest number of rainy days is August (25.9 days).
The month with the least rainy days is November (8.5 days).
Average snowfall days in December
Sullivan's Island, SC
- Average snowfall days in December: 0 days
The month with the highest number of snowfall days is January (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in December /
Average sunshine in December
Sullivan's Island, SC
- Average daylight in December: 10h and 0min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 0min).
- Average sunshine in December: 5h and 4min
The month with the most sunshine is July (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 42min).
Average sunshine days in December
Sullivan's Island, SC
- Average sunshine days in December: 18.5 days
The month with the most sunshine days is January (19.3 days).
The month with the least sunshine days is August (2.8 days).
Average UV index in December
Sullivan's Island, SC
- Average UV index in December: 4
The months with the highest UV index are May, June, July and August (UV index 7).
The month with the lowest UV index is January (UV index 3).
Average cloud cover in December
Sullivan's Island, SC
- Average cloud cover in December: 39
The month with the most cloud cover is December (Cloud cover 39).
The month with the least cloud cover is June (Cloud cover 25).
Average visibility in December
Sullivan's Island, SC
- 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).
Sullivan's Island, South Carolina, USA
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