King Tides Explained

It is winter, so King Tides are here again. “King Tide” has become a popular term recently to explain an especially high tide. King Tide is not a scientifically meaningful term and originated in Australia and New Zealand as a reference to the high tides that occur around Christmas. Of course with the highest highs come the lowest low tides too.

The sizes of our tides change in a repeating and predictable way due to the interplay between the angles, distances and positions of the earth, sun and moon. The sun’s influence is about half that of the moon. Spring tides occur during new and full moons when the earth, moon, and sun are in alignment.

King tides occur 2-3 times a year between November and January when all the influencing factors combine to form “the perfect storm of tides”. First, the earth is as close as it can be to the sun (perihelion). Second, the earth, sun and moon are in alignment (in the position of a spring tide). A King Tide can occur at either a full or a new moon. But it will be one of either! King tide conditions usually persist for three or four days, when the earth, moon, and sun are closest to being in alignment.

Technically, a King Tide is a perigean spring tide, that occurs at perihelion.

There is an organization called the California King Tides Project that is using King Tides to raise awareness of flooding and sea-level rise. The idea is that by observing the effects of super high tides, especially if they occur during winter storms, people can wrap their heads around what will be in store for us as sea level rises with climate change. It’s also an opportunity for citizens to help document the changes to our coast. Check out some photos people have submitted to their California King Tides Photo Initiative Pool.

King Tides 2015/2016

King Tides will occur in 2015/16 on