King Tides & High Tides

Monroe County will experience seasonal high king tides from September through December. King tides are unusually high tides that occur several times a year, usually in the fall, and can cause coastal tidal flooding, especially in low-lying areas. Residents and visitors are encouraged to prepare for king tides, be aware of their surroundings, and avoid driving on flooded streets.

2025 Expected Dates

  • • Sept. 6-12 (Full Moon)
  • • Sept. 19-25 (New Moon)
  • • Oct. 3-25 (Full and New Moon)
  • • Nov. 1-10 (Full Moon)
  • • Nov. 18-20 (New Moon)
  • • Dec. 2-7 (Full Moon)

Check the latest weather forecast at www.weather.gov/key. Heavy rainfall can add to king tide flooding, resulting in deeper water and additional hazards in streets and neighborhoods.

Submit Photos

If done safely, residents can provide photos of property or neighborhoods experiencing tidal flooding to greenkeys@monroecounty-fl.gov with the address, date, and time the photos were taken. Photos can assist in future planning and will become the property of Monroe County. By submitting a photo, you agree to allow the county to use it in any manner the county desires.

How To Stay Safe

  • Avoid walking through floodwaters; it is dangerous and can be a health hazard.
  • Adjust your driving schedule accordingly and do not drive through flooded areas. Turn around and find another way if possible. It is likely saltwater. It is unsafe and can cause short and long-term damage to your vehicle. If you drive through tidal floods, wash the undercarriage of your car to remove any saltwater accumulation.
  • Follow posted road closure and detour signs.
  • If you drive through flooded areas, please note that creating waves can cause additional damage to the surrounding landscaping and property.
  • Avoid parking your vehicle in low-lying areas that are prone to flooding to prevent saltwater damage to your vehicle.
  • Be careful of hazards below the surface that you cannot see, which can cause injury from things like nails, broken glass, debris, and displaced utility hole covers.
  • If you are a boater, be aware that these high tides cause lower clearances under fixed bridges. Check the tides before leaving the dock.

Review additional information on flood insurance rate maps, coastal high hazard areas, property flood depths, natural conservation areas and wetlands, flood insurance, and floodplain management regulations.

High Tide/Low Tide

Knowledge of the tide times and predicted heights is important to various applications such as emergency preparedness, maritime navigation, the construction of docks and seawalls, and the operation of wastewater and stormwater collection systems. Tide information is used for fishing, boating, and other water-related industries.

To find tides in your area, visit https://tidesandcurrents.noaa.gov/map/index.html. (Put in a zip code, or city and state, and it will use the closest station data with today's tides as well as measured water levels.)

Insure Your Property

Homeowner and renter insurance policies usually do not cover flood damage. Monroe County encourages neighbors who rent or own property in the Florida Keys to purchase flood insurance to protect their homes and possessions against loss from flood damage.  

Protect Your Property

Neighbors who drive through tidally flooded streets should consider taking their vehicles through a car wash equipped with an undercarriage sprayer to remove saltwater.

Storm Drains

State law prohibits dumping anything into the storm drain system and unauthorized obstructions or alterations of the drainage features. Residents should report illegal dumping into the stormwater system or clogged storm drains by calling 9-1-1 if they see it happening.

Residents can help prevent flooding and stormwater pollution by:

  • Keeping pollutants or chemicals out of the storm drains
  • Keeping swales, yards, and other surfaces clear of debris so that water can drain into the soil rather than running off and causing flooding
  • Removing debris from nearby storm drains so water may flow freely into them
  • Landscape with native, drought-friendly plants that absorb water and require little or no fertilizer