Weather in Charleston in September 2025
Average weather
Average temperature in Charleston in September
Going from a maximum of +93°F during the day to a minimum of +61°F during the night, the temperature in September averages around +84°F.
The average maximum temperature goes down 11% by the end of the month, compared with the beginning of the month, from +84°F to +81°F.
Is Charleston warm or cold in September?
Charleston is typically warm in September.
Maximum temperatures go down compared to the previous month from +88°F to +82°F. The minimum temperature also goes down from +75°F to +70°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how September is compared to other months in Charleston:
Climate in Charleston in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +88°F | +82°F | +75°F | ||||
| Min. temperature | ||||||
| +61°F | +54°F | +37°F | ||||
| Max. temperature | ||||||
| +100°F | +97°F | +95°F | ||||
| Rainfall | ||||||
| 179 mm | 140 mm | 92 mm | ||||
| Wind | ||||||
| 2 m/s | 3 m/s | 3 m/s | ||||
| Humidity | ||||||
| 82% | 81% | 78% | ||||
| Air pressure | ||||||
| 1015 HPa | 1015 HPa | 1017 HPa | ||||
| Sunny days | ||||||
| 3 | 6 | 12 | ||||
| Cloudy days | ||||||
| 3 | 5 | 7 | ||||
| Rainy days | ||||||
| 23 | 19 | 12 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as ok as in August. It’s getting colder in September. From +88°F in the day, the average maximum temperature lowers to +82°F. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 179 mm to 140 mm. It feels drier, as humidity decreases from 82% to 81%. Winds are stronger in comparison to August, going up from 2 m/s to 3 m/s on average. The good news is there are likely to be more sunny days in September, from 3 to 6.
But maybe it is worth considering traveling in October as the weather gets better.
Wind
The average wind speed is 3 m/s getting up to 6 m/s which is a medium breeze. You can feel it, especially getting out of the water.
The average wind speed in Charleston is gradually decreasing during September, going from 4 m/s to 2 m/s over the course of the month.
Rain
How was the weather last September in Charleston?
Climate Change Over the Years
The climate in Charleston in September has not changed that much over the last 43 years.
The average temperature was the lowest in 1988 (+72°F) and the highest in 2012 (+77°F). The driest year was 2011 with only 770 mm of rainfall, and the wettest year was 2024 with 2044 mm.
FAQ
Is September a good time to visit Charleston?
Can you sunbathe in Charleston in September?
Is Charleston rainy in September?
Is it sunny in Charleston in September?
Other cities in USA
Monthly weather in Charleston
Source of the data
For this page, we’ve looked at the typical weather in Charleston, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.
