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
The beginning of December brings a slight decrease in the average high-temperature, transitioning from a comfortable 62.4°F (16.9°C) in November to a mild 56.3°F (13.5°C). Throughout December, the temperature tends to fall to a consistent average low of 42.3°F (5.7°C).Humidity
The average relative humidity in December is 74%.Rainfall
December is the month with the most rainfall. Rain falls for 11 days and accumulates 3.58" (91mm) of precipitation.Snowfall
Months with snowfall are January through March, November and December. In December, it is snowing for 0.1 days. Throughout December, 0.16" (4mm) of snow is accumulated. Throughout the year, there are 1.3 snowfall days, and 1.06" (27mm) of snow is accumulated.Daylight
The month with the shortest days is December, with an average of 9h and 54min of daylight.On the first day of the month, sunrise is at 7:08 am and sunset at 5:12 pm. On the last day of December, sunrise is at 7:26 am and sunset at 5:22 pm EST.
Sunshine
The month with the least sunshine is December, with an average of 5.3h of sunshine.UV index
January, February and December, with an average maximum UV index of 3, are months with the lowest UV index. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: An average UV index of 3 in December transforms into this advice:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses. Be prepared! The intensity of the Sun's UV radiation can be amplified nearly double due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Sumter in December?
What is the average humidity in December?
What is the wettest month?
How many days does it rain in December?
How many days does it snow in December in Sumter?
What is the month with the shortest days?
What is the average length of the day in December?
When are sunrise and sunset in December?
What is the month with the least sunshine?
How long on average sun shines in December in Sumter?
What are the months with the lowest UV index?
What is the UV index reading in December?
Average temperature in December
Sumter, SC
- Average high temperature in December: 56.3°F
The warmest month (with the highest average high temperature) is July (90.7°F).
The month with the lowest average high temperature is January (52.9°F).
- Average low temperature in December: 42.3°F
The month with the highest average low temperature is July (72.9°F).
The coldest month (with the lowest average low temperature) is January (38.1°F).
Average pressure in December
Sumter, SC
- Average pressure in December: 30.14"Hg
The months with the highest atmospheric pressure are January, November and December (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.97"Hg).
Average wind speed in December
Sumter, SC
- Average wind speed in December: 7.5mph
The windiest months (with the highest average wind speed) are February and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in December
Sumter, SC
- Average humidity in December: 74%
The month with the highest relative humidity is May (76%).
The months with the lowest relative humidity are January and November (70%).
Average rainfall in December
Sumter, SC
- Average rainfall in December: 3.58"
The wettest month (with the highest rainfall) is December (3.58").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in December
Sumter, SC
- Average rainfall days in December: 11 days
The month with the highest number of rainy days is July (20.1 days).
The month with the least rainy days is October (8.5 days).
Average snowfall in December
Sumter, SC
- Average snowfall in December: 0.16"
The month with the highest snowfall is February (0.55").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in December
Sumter, SC
- Average snowfall days in December: 0.1 days
The month with the highest number of snowfall days is February (0.6 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in December /
Average sunshine in December
Sumter, SC
- Average daylight in December: 9h and 5min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in December: 5h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in December
Sumter, SC
- Average sunshine days in December: 18.8 days
The month with the most sunshine days is October (20.8 days).
The month with the least sunshine days is July (8.8 days).
Average UV index in December
Sumter, SC
- Average UV index in December: 3
The months with the highest UV index are June and July (UV index 7).
The months with the lowest UV index are January, February and December (UV index 3).
Average cloud cover in December
Sumter, SC
- Average cloud cover in December: 42
The months with the most cloud cover are February and December (Cloud cover 42).
The month with the least cloud cover is October (Cloud cover 29).
Average visibility in December
Sumter, 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).
Sumter, South Carolina, USA
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