Charleston weather in August
Temperature, sea and sunshine in August: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in August
Good
Best time to visit: May – October
What is the weather like in Charleston in August?
In August, Charleston is hot: daytime highs average 30 °C, and even at night it stays warm at around 25 °C. The sea averages 28.5 °C – lovely and warm for swimming. The sun shines for around 7 hours a day. It rains often – on about 19 days, adding up to 165 mm. On about 12 days the thermometer climbs to 30 °C or more. The air is often humid and muggy. All in all, August is a good month for a holiday in Charleston.
August compared
How the weather changes from July to September. Tap a month to open it.
| JulyJul | AugustAug | SeptemberSep | |
|---|---|---|---|
| Score | 75 | 72 | 77 |
| Day | 30° | 30° | 28° |
| Night | 25° | 25° | 22° |
| Sea | 28° | 29° | 27° |
| Sun | 8 h | 7 h | 6 h |
| Rain days | 18 | 19 | 13 |
More details for August
- Daylight
- 13 h 24 min06:43 – 20:07
- UV index
- 10 · very highclear sky, noon (estimate)All months
- Muggy days
- 31 daysdew point 18 °C or moreAll months
- Wind
- 16 km/haverage daily peakAll months
- Cloud cover
- 60 %on averageAll months
- Hot days
- 12 days30 °C or moreAll months
- Time zone
- UTC−4America/New_York
How the score comes together
- Temperatureweight 35 %100 %
- Seaweight 25 %100 %
- Sunshineweight 20 %62 %
- Few rainy daysweight 20 %0 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in August
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Water bottle – drink plenty
- Insect repellent
- Rain jacket or umbrella
Charleston in August: quick answers
Is Charleston hot in August?
Yes. In August, Charleston is hot: daytime highs average 30 °C and nights stay around 25 °C. On about 12 days the thermometer climbs to 30 °C or more.
Can you swim in Charleston in August?
Yes. In August the sea averages 28.5 °C – lovely and warm for swimming.
Does it rain much in Charleston in August?
It rains often – on about 19 days, adding up to 165 mm.
Charleston month by month
The whole year in CharlestonAll destinations: USAWhere to go in AugustSea temperature in August
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences