Charleston weather in September

Asked whether hurricane season should put them off September, regulars answer with geography and lead time rather than reassurance: the island sits in an unlikely spot for a direct landfall, and a storm that does threaten gives several days of warning, so the decision can be made late. What they sell the month on is the emptiness - the summer crowds have gone, the water is still warm at 28.2C, and the temperatures are comfortable at 29.4C over 22.8C. They are also honest that September is among the wettest months, quoting about five inches; our row has 157.2mm falling across just 7.1 days, twenty-two millimetres each. The record: humidity 79 percent, 9.9 hours of sun and a 19.8 kph wind.

Regulars are specific this counts among the most unpredictable months of the year here, alongside January and early March, a trip landing anywhere from the upper 60s Fahrenheit down to the low 40s depending purely on which weather pattern happens to be passing through. Our row backs that mild, genuinely wet read, 17.5C over 10C nights feeling 7C, with 60mm of rain across 6 days and a real 20.4 kph wind. Regulars are consistent mostly sunshine remains the more common outcome despite the real cold-snap risk, a coat and scarf, maybe gloves, covering most of what's actually needed to stay comfortable. The sea sits at a cold 14.9C. The record: 7.7 hours of sun, humidity 77 percent and AQI 41.

Charleston-forum threads on July weather don't dress it up: temperatures regularly near 90F degrees on the thermometer, but the heat index pushes into triple digits most afternoons, and posters specifically flag downtown's brick and pavement as radiating extra heat back at pedestrians on top of the base forecast. Pop-up afternoon thunderstorms are described as a near-daily feature, arriving fast and hard enough that one side of a street can be pouring while the other stays completely dry - an umbrella is called essential rather than optional. Regulars are split on whether it's worth it: many say the heat and humidity are the only downside and everything indoors runs cold, while others recommend simply waiting for October instead. Early morning is the consistent window regulars suggest for outdoor sightseeing. The record: a scorching 31.3C by day feeling like a punishing 37C, 25.6C nights, 149mm across 11.4 days, 82 percent humidity, a 30.3C sea and 11.4 hours of sun.

Charleston-forum threads on early May weather call it largely comfortable, temperatures in the 70s and 80s Fahrenheit, though posters are honest that humidity can turn oppressive on some days even this early in the season. Mid-to-late May is where it noticeably tips over into genuinely warm and humid, ahead of the full summer swelter still to come. Downtown is also at its busiest in May, one of the year's three peak months alongside April and October, so crowds compound the heat rather than easing it. The record: 29.3C days feeling like a sticky 33C, 23.8C nights, 132mm across 8.4 days, a 25.7C sea, 80 percent humidity and 11.3 hours of sun - warmer and more humid than the largely-comfortable framing suggests by month's end.

November is the month Charleston regulars pick, and several call it their favourite: this is one of the two peak seasons here, spring being the other, because summer is the part locals escape. The weather they describe is good but genuinely unpredictable - it can be above 70F or it can be in the 40s and 50s, with highs around 70 typical and the nights dropping through the 60s into the 50s as the month runs. Our row's 19.9C day over a 12.5C night is the middle of that. Their packing answer is layers plus an umbrella, and their specific warning is not to plan on t-shirts alone, because the gap between early morning and mid-afternoon does the work. The record: 5.8 precipitation days carrying 49.2mm, humidity 75 percent and 7.9 hours of sun.