High Tide Flooding Outlook: September 2026
Mean sea levels are generally higher in the late summer and early fall months, due to warmer temperatures and weather patterns, and this month higher tides can be expected around the new moon, on September 10, and the full moon, on September 26. The mid-Atlantic, Southeast, Gulf Coast, and the Big Island of Hawaii are the regions most likely to see flooding this month, although NOAA predicts only a slight chance (now defined as up to a 20% likelihood of flooding) for most harbors in these areas when utilizing the National Ocean Service’s flooding threshold tied to the Mean Higher High Water datum. Norfolk, Virginia, and the Outer Banks community of Duck, North Carolina, have a more elevated likelihood (up to a 40% chance of high water), as will Port Canaveral, Florida; Galveston Bay, Texas; and Hilo, Hawaii. Harbors on the West Coast, in contrast, are unlikely to see flooding this month. Employing different thresholds — lower than two feet — will increase the prevalence of likely flooding, but at US Harbors we are using the NOS minor flooding threshold as the benchmark, as that has been used previously in our flooding reports.
National Summary
25 harbors have an elevated chance of high tide flooding in September 2026.
- Northeast1 harbor
- Mid-Atlantic7 harbors
- Southeast8 harbors
- Gulf Coast6 harbors
- West Coast0 harbors
- Hawaii3 harbors
Astronomical Factors
- Sep 10 — New moon
- Sep 26 — Full moon
Northeast 1 Harbor
Low lying areas may flood, however high tides alone will likely not cause a significant impact on the coast in most areas unless accompanied by a storm or strong winds. Lower than normal low tides will also occur.
| Harbor | Threshold | Flooding Likelihoods & Dates |
|---|---|---|
| Kings Point, NY | 1.96 ft | Low RiskSep 11–12, 27–30 (peak 18.4%) |
Mid-Atlantic 7 Harbors
Some locations along the Mid-Atlantic coast will have their highest tides of the year. Minor tidal flooding along the coast will occur, particularly in low lying areas. If a storm occurs at this time, increased levels of tidal flooding and coastal erosion may occur. Lower than normal low tides will also occur.
| Harbor | Threshold | Flooding Likelihoods & Dates |
|---|---|---|
| Norfolk, VA | 1.75 ft | Moderate RiskSep 28–30 (peak 22.5%)Low RiskSep 1–4, 6–15, 25–27 (5.8%–18%) |
| Wachapreague, VA | 1.85 ft | Low RiskSep 8–14, 27–30 (peak 13.5%) |
| Lewisetta, VA | 1.70 ft | Low RiskSep 1–3, 6–15, 24–30 (peak 12.3%) |
| Windmill Point, VA | 1.75 ft | Low RiskSep 1–3, 8–14, 26–30 (peak 11.1%) |
| Kiptopeke, VA | 1.76 ft | Low RiskSep 12–13, 28–30 (peak 10.8%) |
| Cape May Canal, NJ | 1.86 ft | Low RiskSep 9–10, 29–30 (peak 8.1%) |
| Lewes, Breakwater Harbor, DE | 1.83 ft | Low RiskSep 29–30 (peak 7.4%) |
Southeast 8 Harbors
Minor tidal flooding along the coast will occur, particularly in low lying areas. If a storm occurs at this time, increased levels of tidal flooding and coastal erosion may occur. Lower than normal low tides will also occur.
| Harbor | Threshold | Flooding Likelihoods & Dates |
|---|---|---|
| Trident Pier, Cape Canaveral, FL | 1.76 ft | Moderate RiskSep 29–30 (peak 23.1%)Low RiskSep 27–28 (6.4%–12.8%) |
| Duck, NC | 1.79 ft | Moderate RiskSep 29 (peak 22.3%)Low RiskSep 8–14, 27–28, 30 (5.5%–19.2%) |
| Fort Pulaski, GA | 1.94 ft | Low RiskSep 8–11, 27–30 (peak 15.2%) |
| Myrtle Beach (Springmaid Pier), SC | 1.86 ft | Low RiskSep 28–30 (peak 9.8%) |
| Charleston, SC | 1.87 ft | Low RiskSep 9, 28–30 (peak 9.1%) |
| Mayport Naval Station, St Johns R, FL | 1.83 ft | Low RiskSep 28–30 (peak 8.4%) |
| Fernandina Beach, FL | 1.90 ft | Low RiskSep 9–10, 28–30 (peak 8.3%) |
| Beaufort, NC | 1.78 ft | Low RiskSep 29–30 (peak 7.5%) |
Gulf Coast 6 Harbors
In many locations of the Gulf Coast, the tidal range is relatively small compared to other regions of the U.S. so they will not be as significantly impacted by a perigean spring tide.
| Harbor | Threshold | Flooding Likelihoods & Dates |
|---|---|---|
| Eagle Point, Galveston Bay, TX | 1.62 ft | Moderate RiskSep 4–8, 16–22, 27–30 (peak 37.8%)Low RiskSep 1–3, 9–15, 23–26 (7.8%–19.8%) |
| Galveston Pier 21, TX | 1.70 ft | Low RiskSep 4–7, 16–21, 27–30 (peak 19.6%) |
| Bay Saint Louis, MS | 1.71 ft | Low RiskSep 3–8, 15–20, 29–30 (peak 15.7%) |
| Cedar Key, FL | 1.79 ft | Low RiskSep 1–5, 8–12, 14–16, 27–30 (peak 14.7%) |
| Dauphin Island, AL | 1.68 ft | Low RiskSep 4–7, 30 (peak 10.4%) |
| Pensacola, FL | 1.69 ft | Low RiskSep 4–8, 30 (peak 9.9%) |
West Coast 0 Harbors
Coastal flooding based primarily on tides is unlikely this month on the West Coast.
Hawaii 3 Harbors
Some stations in the Pacific Islands are predicted to exceed the high tide flooding threshold based on tides alone. Minor tidal flooding along the coast will occur, particularly in low lying areas. If a storm occurs at this time, increased levels of tidal flooding and coastal erosion may occur. Lower than normal low tides will also occur.
| Harbor | Threshold | Flooding Likelihoods & Dates |
|---|---|---|
| Hilo, Hilo Bay, Kuhio Bay, HI | 1.00 ft | Moderate RiskSep 8–9 (peak 33.7%)Low RiskSep 7, 10 (5.9%–16.1%) |
| Kawaihae, HI | 1.00 ft | Low RiskSep 7–9 (peak 10.5%) |
| Kahului, HI | 1.00 ft | Low RiskSep 8–9 (peak 10%) |
Note: A harbor’s absence from this list does not mean flooding is impossible. It means NOAA either has no sufficiently validated model for that location, or the local hydrodynamics make a prediction unreliable. NOAA does not currently model any station in Alaska. Real-time weather can cause flooding at any coastal location regardless of this outlook — within five days, refer to the National Weather Service.
Where the risk is this month
Pin colour shows each harbor’s highest flood likelihood for the month. Select a pin for its dates and threshold.
About this data
- Source
- NOAA Center for Operational Oceanographic Products and Services (CO-OPS), Monthly High Tide Flooding Outlook
- API
- Derived Products API (DPAPI), Daily Likelihoods endpoint
- Threshold
- NOS minor
- Datum
- MHHW
- Units
- English (feet)
- Model run
- August 10, 2026
- Includes
- Harbors with at least one day at or above 5% flood likelihood
Flood likelihoods come from a probabilistic model combining tide predictions, sea level rise trends and seasonal changes in coastal sea level. The model does not account for real-time weather.
