As of February 28, 2026, you can physically enter the water at Rehoboth Beach, but you probably shouldn't for comfort or safety. The Atlantic Ocean temperature in Delaware in late February is typically around 4°C to 6°C (39°F–43°F), which is dangerously cold for anyone without a professional-grade thick wetsuit. Furthermore, while the beach is open year-round, there are no lifeguards on duty during the "off-season," making swimming a high-risk activity. From a health perspective, it is a high-value peer tip to check the DNREC "Swimming Advisory" page; while the water is usually clean in winter, heavy rains can occasionally cause "bacteria spikes" near outfall pipes. For most 2026 visitors, February is a high-value time for a "Boardwalk Walk," tax-free shopping, and enjoying a "Thrasher's Fries" without the lines, rather than for a dip in the ocean. If you are determined to swim, a local "Polar Bear" club event is the only peer-recommended way to do it safely with medical supervision and a warm towel waiting on the sand.