King Tides in Martin County

Martin County will experience seasonal high king tides around the full and new moons from September through December 2021. King tides are extreme high tides that occur several times a year, usually in the fall, that can cause coastal tidal flooding, especially in low-lying areas. This is often called sunny day flooding because it can happen on a cloudless day when no rain is in sight. The impacts of king tides are magnified when they coincide with major storms.

We can use NOAA tide predictions for our area that are based on measurements from a gauge located at Lake Worth Pier to anticipate the dates and ranges of these tides. 

Martin County is monitoring areas that are historically prone to impacts from these high tides. Residents and visitors are encouraged to prepare for king tides, be aware of their surroundings, and avoid driving on flooded streets.

Anticipated 2021 King Tides:

  • September 18 – 23
  • October 5 – 10
  • October 17 – 21
  • November 1 – 6
  • November 17 – 20
  • December 2 – 7

Submit Photos

Help Martin County's resilience team document extreme water levels brought on by King Tides or any unexpected flooding by submitting photos showing high water levels near you. By submitting photos you agree that Martin County, Florida and the resilience planning staff may use them in public information reports, meetings and presentations.

A flooded roadway in Martin County due to King Tides
Image shows 2019 king tide flooding on MacArthur Boulevard in Martin County, Florida. 

What Are King Tides?

The king tides are the highest predicted high tides of the year at a coastal location and can reach elevations substantially above the highest water level typically seen throughout the year. The very high tides occur around the full and new moons and can persist for several days at a time, depending on coincident weather conditions.  King tides are also known as perigean spring tides.

In Martin County, the king tides usually occur during the months of October and November. King tides provide a preview of the more sustained tidal variations we will see in the years to come as sea levels continue to rise.  They also provide real time indicators of areas experiencing the most immediate threat from sea level rise.

You can explore the NOAA infographic below to better understand how perigean spring tides work.

King Tide Impacts

The county has completed several projects to mitigate observed  impacts of tidal flooding. Infrastructure improvements and technology like backflow preventers in drainage pipes, living shorelines, shore hardening and the elevation of structures and critical infrastructure are examples of our recent projects.

The county will continue to evaluate the unique conditions of each local area where nuisance flooding occurs, including flooding during king tides, to develop custom plans specific to the local conditions. Learn more about king tides via the EPA website.