Charleston weather in August
August in Charleston: sweltering, soaked, with very humid — a fair time to visit.
#11 of 12 months in Charleston · #490 of 604 destinations to visit in August · comfort 59/100 (tier D)
Updated June 2026 · climate normals from ERA5 reanalysis
Charleston climate normals — August
| Daytime high | 30°C / 86°F | 🔥 sweltering |
|---|---|---|
| Nighttime low | 25°C / 77°F | |
| Feels like (high) | 35°C / 95°F | |
| Rainfall | 183 mm / 7.2 in | ⛈ soaked |
| Rainy days | 20 days | |
| Humidity | 81% | 💦 very humid |
| Dew point | 24°C / 74°F | |
| Sunshine | 10.4 h/day | |
| Daylight | 13.3 h | |
| Wind | 16 km/h / 10 mph | |
| Air quality (US AQI) | 56 | 🙂 moderate |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Charleston in August — FAQ
- Is August a good time to visit Charleston?
- August in Charleston: sweltering, soaked, with very humid — a fair time to visit. It ranks #11 of 12 months for Charleston on SeasonMap's comfort score (59/100).
- What is the weather like in Charleston in August?
- In August, Charleston averages a daily high of 29.8°C and a low of 25.1°C, with about 183.4 mm of rain over roughly 20.4 rainy days.
- What is the air quality in Charleston in August?
- Charleston has a mean US Air Quality Index of about 56 in August.