High Tide Flooding Outlook for September 2025

The seasonal changes that autumn ushers in — crisp breezes, drier air, and of course colorful leaves — are especially evident on the coast, where we see an increase in flooding potential this month. The Mid-Atlantic, Southeast, and Gulf Coast will see the greatest likelihood for high water events, as flooding is possible in major harbors such as Cape May, NJ, and Charleston, SC, in September. In the Northeast, only Kings Point, NY, will see the possibility of flooding (note that real-time weather conditions, including wind direction and storm surge, may increase the potential for flooding in any location) while the Hawaiian Islands will see possible flooding only in Hilo, on the Big Island of Hawaii. All harbors can expect higher tides on and around the dates of the full moon, on September 7, and new moon (known as spring tides) on September 21. Mean sea level is generally higher in the early fall months due to warmer, expanding ocean water and changes in weather patterns.

Note that while NOAA only makes these flooding predictions for harbors with National Ocean Service water level stations, other locations along the coast may experience similar high-water events during these time periods. In addition, real-time weather conditions, including wind direction and storm surge, may also increase the potential for flooding. In all locations, higher than normal high tides (and lower low tides) should be expected on or around the full moon, on September 7, and the new moon, on September 21.

September 7 – Full Moon
September 21 – New Moon

Make sure to print out the monthly tide chart from USHarbors so that you can stay on top of any potential flooding events in your favorite harbor.

Northeast: Possible & Likely Flood Days

• Kings Point, NY — POSSIBLE September 9-12

Mid-Atlantic: Possible & Likely Flood Days

• Cape May, NJ — POSSIBLE September 10-11
• Lewes, DE — POSSIBLE September 11
• Lewisetta, VA — POSSIBLE September 6-13; 18-23
• Windmill Point, VA — POSSIBLE September 8-13
• Wachapreague, VA — POSSIBLE September 9-13
• Kiptopeke, VA — POSSIBLE September 9-12
• Sewells Point, VA — POSSIBLE September 6-14; 20-25

Southeast: Possible & Likely Flood Days

• Duck, NC — POSSIBLE September 7; 9-13
• Beaufort, Duke Marine Lab, NC — POSSIBLE September 11-12
• Charleston, SC — POSSIBLE September 11
• Fort Pulaski, GA — POSSIBLE September 7-12
• Fernandina Beach, FL — POSSIBLE September 10-12
• Trident Pier, Port Canaveral, FL — POSSIBLE September 10-12

Gulf Coast: Possible & Likely Flood Days