What is the ocean temperature?
Ocean temperatures around Long Island change significantly throughout the year, ranging from the upper 30s and 40s during winter to the upper 60s and 70s during the summer. The warmest water is typically found in August, while February and March are generally the coldest months.
In Short
Long Island’s ocean water is coolest during the winter and gradually warms through the spring, reaching its highest temperatures in late summer. Water temperatures vary depending on location, with beaches along the Atlantic Ocean, Long Island Sound, and the Great South Bay often experiencing slightly different conditions.
What Is the Ocean Temperature Around Long Island?
Ocean temperatures are influenced by seasonal weather patterns, ocean currents, wind direction, and water depth. During the winter months, the Atlantic Ocean surrounding Long Island typically remains in the upper 30s to mid-40s, making swimming uncomfortable without specialized cold-water gear.
As spring progresses, water temperatures slowly rise before reaching their warmest levels during July, August, and early September. Late summer is generally considered the best time for swimming, surfing, paddleboarding, kayaking, and other water activities because the ocean has had several months to warm.
Water temperatures along the Long Island Sound and the Great South Bay are often slightly warmer than those along the open Atlantic Ocean during parts of the summer because these more protected waters heat more quickly.
Current water temperatures can change daily due to weather, tides, and ocean conditions. Visitors planning to swim, surf, fish, or boat should check the latest water temperature and marine forecast before heading to the beach.
Typical Water Temperatures
| Season | Typical Water Temperature |
|---|---|
| Winter (Dec–Feb) | Upper 30s°F to mid-40s°F (about 3–7°C) |
| Spring (Mar–May) | Mid-40s°F to upper 50s°F (about 7–15°C) |
| Summer (Jun–Aug) | Mid-60s°F to mid-70s°F (about 18–24°C) |
| Fall (Sep–Nov) | Upper 60s°F gradually cooling into the 50s°F (about 10–21°C) |
| Warmest Month | Typically August. |
Whether you’re planning a beach vacation, surfing session, fishing trip, or boating adventure, understanding Long Island’s seasonal water temperatures can help you prepare for the conditions you’ll encounter. Late summer generally offers the warmest and most comfortable water for recreational activities, while winter brings much colder conditions throughout the region.
