South Carolina, USA
Long term weather forecast
Long term weather forecast

September weather forecast and Climate
Charleston, SC

  • Average high temperature in September: 84.8°F

Warmest month (with highest average high temperature) is July (91.1°F).
Month with lowest average high temperature is January (59°F).

  • Average low temperature in September: 67.2°F

Month with highest average low temperature is July (73°F).
Coldest month (with lowest average low temperature) is January (37.5°F).

  • Average humidity in September: 78.2%

Month with highest relative humidity is August (78.9%).
Month with lowest relative humidity is February (67.4%).

  • Average rainfall in September: 6.1"

Wettest month (with highest rainfall) is August (7.2").
Driest month (with lowest rainfall) is November (2.4").

  • Average rainfall days in September: 10 days

Month with highest number of rainy days is August (13.2 days).
Month with lowest number of rainy days is November (7 days).

  • Average snowfall in September: 0"

Month with highest snowfall is December (0.5").
Months with lowest snowfall are January, March, April, May, June, July, August, September, October and November (0").

  • Average snowfall days in September: 0 days

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

  • Average sea temperature in September: 82°F

Best month for swimming (with highest average sea temperature) is August (84°F).
Coldest months (with lowest average sea temperature) are January, February and March (70°F).

  • Average daylight in September: 12h

Months with longest days are May, June and July (Average daylight: 14).
Months with shortest days are January, November and December (Average daylight: 10).

  • Average sunshine in September: 7.3h

Month with most sunshine is May (Average sunshine: 9.5).
Month with least sunshine is December (Average sunshine: 5.5).

  • Average UV index in September: 8

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