The highest tides of the year are here, and they could bring flooding even in areas or during times when it is not raining.
They occur due to the combined gravitational forces of the Sun and Moon, which pull on the Earth's oceans, creating the highest tides of the year. King Tides typically occur twice a year, more frequently on the east coast of Florida, as well as along the entire Eastern Seaboard. They are not particularly noticeable along the west coast of Florida or much of the Gulf Coast due to the bathymetry or steepness of the sea floor, which has a shallow continental shelf.
The moon has entered its full moon phase. During this time, it is also in its closest orbit to Earth, perigee. Perigee will happen on September 10. King tides bring higher-than-normal high tides and also lower-than-normal low tides.
The high tides have been increasing and are expected to reach a peak on Tuesday. On average, high tides will be approximately 1 foot higher than usual. For example, in Miami Beach, the average high tide is about 2.5 feet. However, during the morning high tides of September 9th and 10th, which occur between 10 a.m. and 11 a.m., the level will be 3.6 feet—similar conditions, aside from different levels, all along Florida's East Coast.
Sea level rise is also contributing to higher-than-normal tides. The mean sea level is typically higher in the summer due to changing weather patterns and increasing water temperatures.
Heavy downpours worsen the flooding
These higher-than-normal tides could result in minor flooding along the coast, and coastal erosion may also occur. Luckily, the wind is not coming straight from the east during this round of King Tides. In past years, a high-pressure system has been located over the northern Atlantic, which has driven more water toward the east coast, exacerbating coastal flooding. This year, although we don't have this high, there is a stationary front and another front that will become stagnant over Central Florida, producing numerous strong storms. As the day heats up, these storms will intensify, resulting in torrential downpours. This same setup has been present since last week, with several fronts becoming stagnant over the central and southern portions of the state.
4:58 PM | A Flood Advisory has been issued for portions of Lake County until 6:15 PM EDT. Between 2 and 2.5 inches of rain have fallen. Additional rainfall amounts of 1 to 1.5 inches are expected over the area. #FLwx pic.twitter.com/bNUyTacOfG
— NWS Melbourne (@NWSMelbourne) September 8, 2025
Florida's forecast
The flash flood risk will persist throughout the entire Peninsula part of the state for the remainder of the week. Overall, there could be between 2 and 5 inches through Friday. However, keep in mind that some storms may develop these amounts in certain areas during just one afternoon this week. Isolated spots could receive over 6 inches of rain.
There are 5 Flood Advisories and 1 Flash Flood Warning currently out for metro Miami-Dade, Broward, and Palm Beach counties.
— NWS Miami (@NWSMiami) September 8, 2025
Exercise caution if you will be out on the roads during rush hour. pic.twitter.com/utrmFrDkZl
Early models indicate that the cold front could move far enough south to clear Central Florida by the end of this week, but it may remain close enough to South Florida to continue bringing higher-than-normal rain and storm chances.
These stagnant fronts need to be watched closely, not only because they bring more storm activity, increasing the flood risk, but there are times when enough energy is left behind over water, which can quickly spin off into a tropical system. Currently, this is not happening, but it serves as a timely reminder that we are still in hurricane season and must remain weather-aware, with a plan in place in case a storm threatens your area.
