August Weather in Charleston, United States

Last updated: June 24, 2025

In August, the average temperature in Charleston, United States reaches a comfortable 25°C (78°F). However, temperature can vary significantly, with minimums dipping to 13°C (56°F) and maximums soaring up to 35°C (96°F). Expect precipitation of about 102 mm (4.0 in) spread over 10 days, while the air maintains a high average humidity of 76%.

August Temperature in Charleston

In August in Charleston, the average temperature is 25°C (78°F). Maximums can reach 35°C (96°F), and minimums can be as low as 13°C (56°F). It's an ideal time for travelers to enjoy mild weather with opportunities for both warm days and cooler evenings.

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

The chart illustrates August 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, August typically has an average temperature of 25°C (78°F), with highs reaching up to 35°C (96°F) and lows dropping to around 13°C (56°F).

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

August Precipitation in Charleston

In Charleston in August, the total precipitation amount is 102 mm (4.0 in) falling over the course of 10 days.

August Precipitation Trends in Charleston

The chart displays monthly precipitation patterns in Charleston, with values for each month alongside August’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August’s conditions compare to those of other months. In Charleston, August typically receives around 102 mm (4.0 inches) of precipitation spread over approximately 10 days.

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

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Millimeters (mm) Inches (in)

August Humidity in Charleston

In Charleston in August humidity is 76%. With an average temperature of 25°C (78°F), this humidity feels like a thick blanket wrapping around you, making every step feel heavier and the air thick, causing travelers to seek shade and refreshment more often.

August Average Humidity in Charleston

This chart illustrates the average monthly humidity levels in Charleston, with August’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In August, average humidity in Charleston is approximately 76%, offering insight into how humid the weather typically is during this month.

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

August UV Index in Charleston

In Charleston in August, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Charleston.

Maximum UV Index Levels in Charleston for August

The chart shows the monthly maximum UV Index (UVI) for Charleston in August, 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 August, the maximum UV index in Charleston typically reaches 10, which falls under the very high exposure category.

Data source: Charleston August 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 August 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 August’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 August’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	3°C (38°F)	110 mm (4.3 inches)	86%	moderate
February Weather	5°C (41°F)	139 mm (5.5 inches)	84%	high
March Weather	10°C (51°F)	169 mm (6.6 inches)	84%	high
April Weather	14°C (58°F)	140 mm (5.5 inches)	80%	very high
May Weather	21°C (70°F)	151 mm (6.0 inches)	82%	extreme
June Weather	25°C (78°F)	112 mm (4.4 inches)	83%	extreme
July Weather	27°C (81°F)	101 mm (4.0 inches)	79%	very high
August Weather	25°C (78°F)	102 mm (4.0 inches)	76%	very high
September Weather	23°C (74°F)	85 mm (3.3 inches)	75%	very high
October Weather	16°C (62°F)	122 mm (4.8 inches)	74%	high
November Weather	8°C (47°F)	101 mm (4.0 inches)	85%	moderate
December Weather	6°C (43°F)	97 mm (3.8 inches)	88%	moderate