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Charleston Weather by Month
Average temperatures, rainfall and humidity for Charleston, United States, month by month, built from OpenWeather's historical records. Use it to see what a typical Charleston month looks like before you travel — then check the live Charleston forecast for the days ahead.
Warmest month
July
32°C average high
Coolest month
January
5°C average low
Wettest month
September
180 mm of rain
Driest month
May
54 mm of rain
Average temperature and rainfall in Charleston by month
Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.
| Month | Avg high | Avg low | Record low / high | Rainfall | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 15°C | 5°C | -9°C / 27°C | 65 mm | 75% | 12 km/h |
| February | 18°C | 8°C | -8°C / 29°C | 57 mm | 76% | 13 km/h |
| March | 21°C | 10°C | -3°C / 30°C | 68 mm | 71% | 14 km/h |
| April | 24°C | 14°C | 2°C / 31°C | 56 mm | 73% | 14 km/h |
| May | 28°C | 19°C | 8°C / 38°C | 54 mm | 76% | 13 km/h |
| June | 30°C | 22°C | 14°C / 37°C | 68 mm | 79% | 12 km/h |
| July | 32°C | 24°C | 18°C / 37°C | 85 mm | 81% | 11 km/h |
| August | 31°C | 24°C | 18°C / 37°C | 98 mm | 83% | 10 km/h |
| September | 29°C | 21°C | 12°C / 36°C | 180 mm | 83% | 11 km/h |
| October | 25°C | 16°C | 2°C / 33°C | 68 mm | 79% | 11 km/h |
| November | 20°C | 10°C | -2°C / 28°C | 65 mm | 78% | 12 km/h |
| December | 17°C | 8°C | -8°C / 27°C | 78 mm | 80% | 11 km/h |
Best time to visit Charleston
The most comfortable time to visit Charleston is generally April to May and October, balancing mild daytime temperatures against the driest stretch of the year. The city has a moderate seasonal swing and rain concentrates around September, totalling about 941 mm a year.
Travellers who prefer heat should aim for July, when highs average 32°C. September is the month to avoid if rain would spoil your plans — it averages 180 mm, roughly 3× the rainfall of May.
Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the Charleston forecast for what is happening now.