Verdict: Excellent month
Charleston Weather in September
September runs warm in Charleston, with daily highs around 28°C (82°F) and nights near 21°C (70°F). Expect showers on roughly 13 days of the month — rarely trip-ruining, worth planning around. Overall, September is one of the best months of the year to be in Charleston.
Average high
28°C / 82°F
Average low
21°C / 70°F
Rain days
~13
Precipitation
147 mm
What to pack for Charleston in September
- Summer clothes, plus one light layer for air-con and evenings
- High-SPF sunscreen, sunglasses, and a refillable water bottle
- Rain gear is non-negotiable — expect rain on roughly 13 days
- Comfortable walking shoes — every guide on this site assumes you'll use them
September against the rest of the year
Warmest in Charleston: Jul (31°C / 88°F) · Coolest: Jan (15°C / 59°F) · Wettest: Aug (~20 rain days)
15°
7°
Jan
17°
9°
Feb
20°
12°
Mar
23°
15°
Apr
26°
19°
May
29°
23°
Jun
31°
25°
Jul
30°
24°
Aug
28°
21°
Sep
24°
17°
Oct
20°
12°
Nov
16°
8°
Dec
Daily highs / lows in °C · bars show rain days per month · ERA5 climate normals (2020–2024)