The highest day temperature in May 2025 was 85°F. The lowest night temperature was 38°F. The average values for day and night temperatures during May were 70.8°F и 55.7°F respectivly.

Most of the days in May are gloomy but you can also expect sunny days.

Precipitation total in May for Charleston is 1.5 in. It makes may one of the most rainy months of the year.

The average wind speed in May is 5.4 mph. This value is relatively stable throughout the year.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Charleston in May is 6.3 hours.