Click on a day for an hourly weather forecast
The weather in Charleston in September is very hot. The average temperatures are between 23°C and 29°C, drinking water regularly is advisable.
You can expect rain for roughly half of the month of September in Charleston. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Charleston in September 2025.
If you’re planning to visit Charleston in the near future, we highly recommend that you review the 14 day weather forecast for Charleston before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 14° / 7° | 5 | 25 | 1 | 91 mm | Good | Charleston in January |
| February | 16° / 9° | 6 | 23 | 0 | 120 mm | Good | Charleston in February |
| March | 19° / 12° | 6 | 25 | 0 | 131 mm | Good | Charleston in March |
| April | 23° / 16° | 6 | 24 | 0 | 131 mm | Perfect | Charleston in April |
| May | 26° / 20° | 8 | 23 | 0 | 165 mm | Good | Charleston in May |
| June | 30° / 24° | 11 | 19 | 0 | 217 mm | Ok | Charleston in June |
| July | 31° / 25° | 14 | 17 | 0 | 260 mm | Ok | Charleston in July |
| August | 31° / 25° | 15 | 16 | 0 | 346 mm | Ok | Charleston in August |
| September | 29° / 23° | 8 | 22 | 0 | 229 mm | Ok | Charleston in September |
| October | 25° / 18° | 5 | 26 | 0 | 161 mm | Perfect | Charleston in October |
| November | 19° / 12° | 4 | 26 | 0 | 87 mm | Good | Charleston in November |
| December | 16° / 10° | 6 | 25 | 0 | 130 mm | Good | Charleston in December |