Charleston Weather in May

The climate in Charleston during May can be summarized as warm, humid and a little damp.

May is in the spring in Charleston and is typically the 5th warmest month of the year. Daytime maximum temperatures average around a muggy 27°C (80°F), whilst at night 19°C (66°F) is normal.

On average May is the 6th wettest month of the year in Charleston with around 95mm 3.7 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.1 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Charleston in May 2025.