Best Times to Visit Charleston, SC. The wettest season is Autumn with 36% of yearly precipitation and 19% occurs in Summer, which is the driest season. There is significant rainfall throughout the year in Charleston. Relative humidity is probalby the second most popular factor that people take into consideration when looking for the weather of a city to live in. Precipitation data includes both calendar year and water year totals, percent of normal values, and comparisons to normal. Charleston has a temperate climate with hot summers and some rainfall in all months. Weather in Charleston, SC : Charleston South Carolina Weather. Based on weather reports collected during 1985–2015. Even the driest month still has a lot of rainfall. Charleston Weather Forecasts. CityRating.com offers the average Charleston relative humidity chart that displays the annual and monthly humidity percentages for Charleston … This product is available for up to 2 months. And Charleston is a beach town, so be sure to spend some time at one of the beaches near Charleston, SC. The best time to visit Charleston is from March to May or from September to November when temperatures are mild – but not stifling. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec The climate guide for Charleston, South Carolina shows long term monthly weather averages processed from data supplied by CRU (University of East Anglia) , the Met Office & the Netherlands Meteorological Institute . Weather Underground provides local & long-range weather forecasts, weatherreports, maps & tropical weather conditions for the Charleston area. Average annual temperatures, rainfall, sunrise and sunset times for Charleston SC. Annual Weather Averages Near Charleston Averages are for Charleston Air Force Base Reporting Station, which is 10 miles from Charleston. August is the wettest month in Charleston with 6.7 inches of rain, and the driest month is May with 2.5 inches. DAILY CLIMATE REPORT - issued daily: Detailed daily weather statistics (usually for yesterday), including temperature, precipitation, degree days, wind, humidity, sunrise/sunset, and record temperature data for the following day. The Charleston lies on 9m above sea level Charleston's climate is classified as warm and temperate. The annual rainfall of 48.3 inches in Charleston means that it is wetter than most places in South Carolina. Charleston Has 4 Seasons: Fall, Winter, Spring, and Marsh Hell July is the start of the hottest months of the year. The average annual temperature in Charleston is 18.7 °C | 65.6 °F. This climate is considered to be Cfa according to the Köppen-Geiger climate classification. This weather chart will help you plan your vacation or wedding in Charleston.