Climate Insights for Charleston

The climate in Charleston is temperate. The average annual temperature is 16°C and approximately 1330mm of precipitation falls per year. Charleston receives a notable amount of rainfall throughout the year, including during its driest month. Charleston is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: July, June, August. The coldest months are January, February, December, when temperatures can drop to -1°C. Light snow can occur between January and November.

Temperatures in Charleston vary considerably across the year, with a 33°C difference between the coldest and warmest months. The warmest month is July, when average highs reach 32°C and the mean temperature sits around 27°C. The coldest month is January, when overnight lows fall to -1°C and the daily average is 3°C. On average, daily temperatures fluctuate by about 10°C between overnight lows and afternoon highs. The sharpest temperature change occurs between October and November, with a 7°C shift in average temperatures.

Charleston is a fairly wet location, receiving approximately 1330mm of precipitation annually, which averages out to around 111mm per month. The wettest month is March, averaging 162mm of rainfall. April and May also tend to see above-average precipitation. The driest month is September, with just 71mm. That's 91mm less than March, the wettest month. Rainfall is relatively evenly distributed throughout the year, so there is no pronounced dry or wet season to plan around. Light snowfall can occur between January and November, totalling around 16cm annually. February is the snowiest month with approximately 6cm.

Charleston is mildly breezy, with an average annual wind speed of 16km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is April, averaging 20km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 13km/h, making it an ideal period for wind-sensitive activities. There is moderate seasonal variation in wind speed, with a 7km/h gap between the calmest and windiest months. Wind tends to be stronger during winter months, driven by seasonal pressure systems. The seasonal averages break down to 18km/h in winter, 19km/h in spring, 14km/h in summer, 15km/h in autumn.

It is currently spring in Charleston, which began on March 20, 2026. Charleston is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in July at around 32°C, while the coldest stretch bottoms out in January near -1°C. Summer is next, beginning on June 21, 2026 — 92 days from now.

The best time to visit Charleston is during September and October, when the weather is most comfortable for travellers. During these months, average temperatures hover around 20°C with modest rainfall averaging 82mm per month. By contrast, July can be uncomfortably hot with highs reaching 32°C, while January is the coldest period with lows dropping to -1°C. Despite being the best months overall, some rain is still likely — pack a waterproof layer and plan a mix of indoor and outdoor activities.

The table below shows monthly climate averages for Charleston based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.