The Atlantic Ocean at Folly Beach runs cold in winter and warm in summer — but the specifics matter when you're planning a trip. Here's exactly what the water temperature looks like month by month, what it means for swimming and surfing, and when the ocean is at its best.
Month by Month Water Temperature
January — February: 50-55°F The coldest months. Comfortable swimming is not realistic without a wetsuit. Serious surfers are in the water with 4/3 wetsuits and hoods. The beach is nearly empty and the waves are often the best of the year.
March: 55-60°F Still cold for casual swimming but improving. A 3/2 wetsuit is appropriate for surfers. By late March the water starts to feel less brutal. Air temperatures are mild and the beach is uncrowded.
April: 60-65°F Getting closer. Some hardy swimmers jump in — most people wait. Surfers are in spring suits. The shoulder season is underway and Folly Beach is genuinely pleasant without summer crowds.
May: 65-70°F The water becomes noticeably more inviting. By mid-to-late May most people are comfortable swimming, especially on warm days when the air temperature makes getting out more bearable. This is when the beach starts filling up.
June: 72-76°F Summer swimming begins in earnest. No wetsuit needed for swimming or surfing. The water is warm enough to stay in for extended periods. Beach crowds pick up significantly.
July — August: 80-84°F Peak warmth. The Atlantic at Folly Beach in July and August is genuinely warm — bath-like on the hottest days. This is the most popular time for beach visits and the water temperature is a big reason why. No gear needed beyond a swimsuit.
September: 78-82°F The water stays warm well into fall. September is the sweet spot — summer water temperatures, noticeably fewer crowds, lower accommodation rates. Locals consistently call September the best month on Folly Beach and the water temperature is part of why.
October: 70-75°F Still comfortably swimmable for most people, especially on warm days. The air cools faster than the water, so the ocean can feel warmer than expected in October. Surfers are back in light spring suits toward the end of the month.
November: 62-68°F The window for casual swimming closes for most visitors. The water is cold enough to be uncomfortable for anything beyond a quick dip. Surfers are back in full wetsuits. The beach is quiet and beautiful.
December: 55-62°F Winter conditions setting in. Wetsuit required for any meaningful time in the water. The dedicated surf community is out year-round regardless.
What This Means for Planning Your Visit
If swimming is your priority: June through September gives you the warmest water. September is the best combination of warm water and reduced crowds. July and August are peak season with the warmest temperatures but maximum crowds.
If surfing is your priority: Fall and winter bring the best waves. The water is cold but manageable with the right wetsuit. A 4/3 wetsuit handles everything from November through March comfortably.
If shoulder season appeals to you: May and October offer comfortable swimming with significantly reduced crowds and lower prices on accommodation. The water in May is still cool for some people — October is generally more comfortable.
Jellyfish and Sea Life
The warmer months bring jellyfish to Folly Beach. Moon jellyfish are common and generally not dangerous — their sting is mild. Portuguese man-of-war, which can cause a more serious sting, occasionally washes up after storms. Checking the beach conditions before swimming during jellyfish season is sensible.
Dolphins are present year-round in the waters around Folly Beach but are most active and visible in warmer months when they're feeding in the tidal creeks and near the surf zone.
Tide and Conditions
Water temperature is only one variable for a good swim or surf session. Check the complete Folly Beach rules for swimming zone restrictions, and our Folly Beach surfing guide for everything you need to know about conditions before paddling out.