King Tides
When the Ocean Reaches its Peak
King Tides are the highest tides of the year, occurring when the gravitational forces of the Moon and Sun align in a way that maximizes their pull on Earth’s oceans. These natural astronomical events offer a glimpse into future sea levels and can lead to significant coastal impacts.
On this page, you’ll explore what causes King Tides, their potential effects on coastlines worldwide, and how these extreme high water events are increasingly influenced by a changing climate. Prepare to understand the dynamic dance between celestial mechanics and our planet’s waters.
Notice the Orbit Shape: The orbit is not a perfect circle. When the Moon is on the Right (0Β°), it is physically closer to Earth (Perigee) AND aligned with the Sun.
Global King Tide Watchlist: 2026β2030
Approximate Astronomical High Tide Windows by Coastal Region
What is a King Tide?
The term "King Tide" is not a scientific definition, but a popular name for an exceptionally high tide. Scientists refer to these events as Perigean Spring Tides. They occur when the gravitational forces of the moon and the sun align in a specific, powerful geometry, pulling the ocean's surface to its absolute limit.
While ordinary high tides happen twice a day, King Tides are rare, occurring only a few times per year. They act as a preview of the futureβshowing us what average sea levels might look like in the coming decades due to climate change.
The Mechanics of the Flood
As demonstrated in the simulator above, a King Tide requires a "Perfect Storm" of orbital mechanics. It isn't enough for the moon to be full; it must also be close.
When the moon is at Perigee (closest approach), it is roughly 30,000 miles closer to Earth than at Apogee (farthest). When this coincides with a New or Full Moon, the solar and lunar gravities stack on top of each other. This combined force bulges the ocean outward, causing water levels to rise 1 to 2 feet higher than a standard high tide. In places like California, Oregon, and Florida, this often pushes the water line past beaches and onto highways.
β οΈ Coastal Safety Warning
King Tides are beautiful but dangerous. They dramatically shrink beaches, often leaving no dry sand for walking. They also increase the risk of Sneaker Wavesβlarge, powerful surges that can sweep people off rocks without warning. During these events, always keep a safe distance from the surf zone and never turn your back on the ocean.
Frequently Asked Questions
About King Tides and Extreme High Water Events
What are King Tides?
King Tides are exceptionally high tides that occur naturally when there is a strong alignment of the gravitational pull between the moon and the sun. This happens a few times each year, often when the moon is closest to Earth (perigee) and in its new or full phase.
Why are they called "King Tides"?
The term "King Tide" is an informal, non-scientific term used to describe these highest annual tides. It originated in Australia and New Zealand but has become widely adopted to distinguish them from regular high tides.
Do King Tides cause flooding?
Yes, King Tides can lead to coastal flooding, often referred to as "sunny day flooding" or "nuisance flooding," even without significant rainfall or storms. They can cause water to overflow storm drains, inundate low-lying roads, and flood coastal properties.
Are King Tides related to climate change?
While King Tides are natural astronomical events, sea level rise due to climate change exacerbates their impacts. As global sea levels increase, these already extreme high tides reach even higher, leading to more frequent and severe coastal flooding.
When do King Tides occur?
The exact timing of King Tides varies globally, but they typically occur a few times a year. They are most noticeable during the new and full moon phases when the moon is closest to Earth (perigee), and during certain seasons when the Earth's orbit brings it closer to the sun.
How can I prepare for a King Tide?
If you live in a coastal area prone to flooding, you can prepare by moving vehicles from low-lying areas, securing property, monitoring local tide forecasts and weather alerts, and having an emergency plan in place. Information is often available from local government or environmental agencies.
Official Tide Data & Forecasts
For the most precise and up-to-date tide predictions, water levels, and current observations, consult the official source for U.S. waters from NOAA.
π Explore NOAA Tides & Currents