Define King Tide: While the term ‘king tide’ is not a scientific term, it is used to describe the highest high tide events of the year, when there is alignment of the gravitational pull between sun and moon. During these extra high tide events, we can see what average water level events might look like in the future, given projected rates of sea-level rise.

  • When king tides occur during floods or storms, they have the potential to cause significant damage to property and coastline.
  • King tides are natural and predictable.

How tides work:

The moon and sun both apply gravitational pull on the Earth’s oceans causing us to experience high and low tides each day. The earth and the moon both have elliptical orbits, which means that the distance between the moon, earth, and sun is constantly changing. When the sun and moon align so as to be tugging from the same direction and the Earth and moon are positioned at the closest points in their orbits, the gravitational pull becomes strongest causing times of greater tidal extremes.

Here are some helpful definitions:

  • Syzygy– Linear alignment of the sun, moon, and Earth, which occurs during the new and full moon, causes the respective gravitational pulls of the sun and moon to reinforce each other.
  • Spring Tide– The effect of syzygy causes an increase in the tidal range.
  • Perigee– Occurs when the moon reaches the closest point to the Earth during its elliptical orbit.
  • Perigean Spring Tide– Occurs when the moon is closest to the Earth during a spring tide.
  • Perihelion– Occurs when the Earth is closest to the sun in its elliptical orbit.

Twice a year when the earth, sun, and moon line up when the moon and the sun are at perigee and perihelion, we generally experience the greatest tidal ranges of the year. These resulting tides have informally been dubbed KING TIDES.