September weather forecast and climate
Charleston, SC

Trees along both sides of a street in Charleston, South Carolina, seen in the twilight light
Trees along both sides of a street in Charleston, South Carolina, seen in the twilight light

What is the temperature in September in Charleston?

The average high-temperature, in September, in Charleston, South Carolina, is 84.7°F (29.3°C), while the average low-temperature is 67.3°F (19.6°C).

How many days does it rain in September in Charleston?

In Charleston, South Carolina, in September, during 10 rainfall days, typically 6.1" (154.9mm) of precipitation is accumulated.
Average temperature in September - Charleston, SC
  • Average high temperature in September: 29.3°C

The warmest month (with the highest average high temperature) is July (32.8°C).
The month with the lowest average high temperature is January (15°C).

  • Average low temperature in September: 19.6°C

The month with the highest average low temperature is July (22.8°C).
The coldest month (with the lowest average low temperature) is January (3.1°C).

Average humidity in September - Charleston, SC
  • Average humidity in September: 78.2%

The month with the highest relative humidity is August (78.9%).
The month with the lowest relative humidity is February (67.4%).

Average rainfall in September - Charleston, SC
  • Average rainfall in September: 154.9mm

The wettest month (with the highest rainfall) is August (181.6mm).
The driest month (with the lowest rainfall) is November (61.7mm).

Average rainfall days in September - Charleston, SC
  • Average rainfall days in September: 10 days

The month with the highest number of rainy days is August (13.2 days).
The month with the lowest number of rainy days is November (7 days).

Average snowfall in September - Charleston, SC
  • Average snowfall in September: 0mm

The month with the highest snowfall is December (12.7mm).
Months with the lowest snowfall are January, March, April, May, June, July, August, September, October and November (0mm).

Average snowfall days in September - Charleston, SC
  • Average snowfall days in September: 0 days

Months with the highest number of snowfall days are February and December (0.2 days).
Months with the lowest number of snowfall days are March, April, May, June, July, August, September, October and November (0 days).

Average sea temperature in September - Charleston, SC
  • Average sea temperature in September: 27.6°C

The best month for swimming (with the highest average sea temperature) is August (28.6°C).
The coldest month (with the lowest average sea temperature) is February (16.7°C).

Average daylight in September / Average sunshine in September - Charleston, SC
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.3h).
The month with shortest days is December (Average daylight: 10h).

  • Average sunshine in September: 7.3h

The month with most sunshine is May (Average sunshine: 9.5h).
The month with least sunshine is December (Average sunshine: 5.5h).

Average UV index in September - Charleston, SC
  • Average UV index in September: 8

Months with the highest UV index are June, July and August (UV index 10).
Months with the lowest UV index are January and December (UV index 3).

deutscheenglishespañolрусский中文