December Weather in Charleston, United States

Last updated: June 24, 2025

In December, the average temperature in Charleston, United States hovers around 5°C (41°F). While the minimum can drop to a chilly -13°C (8°F), temperatures can occasionally peak at a pleasant 21°C (70°F). Expect about 124 mm (4.9 in) of precipitation spread over 12 days, contributing to a notable average humidity of 86%.

December Temperature in Charleston

In December in Charleston, the average temperature is 5°C (41°F). Maximums can reach 21°C (70°F), while minimums can plummet to as low as -13°C (8°F). Be prepared for a wide range of temperatures when traveling during this time.

December Weather in Charleston: Daily Temperature Highs, Lows, and Averages

The chart illustrates December temperature patterns in Charleston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Charleston, December typically has an average temperature of 5°C (41°F), with highs reaching up to 21°C (70°F) and lows dropping to around -13°C (8°F).

Data source: Temperature data for Charleston generated using information from the Copernicus Climate Change Service.

December Precipitation in Charleston

In Charleston in December, the total precipitation amount is 124 mm (4.9 in) over a span of 12 days.

December Precipitation Trends in Charleston

The chart displays monthly precipitation patterns in Charleston, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Charleston, December typically receives around 124 mm (4.9 inches) of precipitation spread over approximately 12 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Charleston

In Charleston in December humidity is 86%. With an average temperature of 5°C (41°F), this humidity feels like a heavy, damp blanket wrapping around you, making outdoor activities uncomfortable and travel quite challenging due to the chill combined with the stickiness in the air.

December Average Humidity in Charleston

This chart illustrates the average monthly humidity levels in Charleston, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Charleston is approximately 86%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Charleston

In Charleston in December, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Charleston, you can check the information here.

Maximum UV Index Levels in Charleston for December

The chart shows the monthly maximum UV Index (UVI) for Charleston in December, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In December, the maximum UV index in Charleston typically reaches 3, which falls under the moderate exposure category.

Data source: Charleston December UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How December Weather in Charleston Compares to Other Months

Weather in Charleston varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Charleston, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Charleston, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	2°C (37°F)	101 mm (4.0 inches)	88%	moderate
February Weather	5°C (42°F)	152 mm (6.0 inches)	88%	moderate
March Weather	9°C (48°F)	119 mm (4.7 inches)	88%	high
April Weather	13°C (56°F)	134 mm (5.3 inches)	86%	very high
May Weather	19°C (66°F)	159 mm (6.3 inches)	82%	very high
June Weather	22°C (72°F)	154 mm (6.1 inches)	84%	very high
July Weather	25°C (77°F)	124 mm (4.9 inches)	82%	very high
August Weather	23°C (74°F)	114 mm (4.5 inches)	73%	very high
September Weather	21°C (70°F)	103 mm (4.0 inches)	73%	very high
October Weather	16°C (61°F)	117 mm (4.6 inches)	81%	high
November Weather	8°C (46°F)	78 mm (3.1 inches)	89%	moderate
December Weather	5°C (41°F)	124 mm (4.9 inches)	86%	moderate