What are the King Tides?

For a great overview of the California King Tides Initiative, the Thank You Ocean campaign has produced a podcast about the Initiative, featuring Marina Psaros of the San Francisco Bay National Estuarine Research Reserve. Check it out here, or on the video below.


“King Tides” are high tides that occur when the gravitational pull of the sun and the moon are in alignment. When these tides happen at the same time as stormy weather (as is often the case during California’s winters), water levels can rise even higher. These high water levels can show us how higher sea levels due to climate change might impact our communities in the future.

While tides themselves are not affected by climate change, the climate and weather do influence coastal sea levels through storm surges, the El Niño/La Niña-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) cycles and other factors. Resulting high tides from a c combination of these conditions can cause widespread damage from flooding and erosion.


Seasonal high tide events can provide a preview of what we might experience regularly in the future as a result of rising sea levels. The King Tide Photo Initiative is an opportunity to share what you see in your community with others through Flickr. Everyone is welcome to participate!

The objectives of the King Tide Photo Initiative are to:

  • Engage Californians in a conversation about the future of our beloved coastal areas
  • Identify and catalog coastal areas that are currently vulnerable to tidal inundation
  • Build an online resource of images that can be used by everyone – be that artists, high school students, public servants, non-profit organizations, scientists – to communicate about coastal hazards


Increases in global sea levels have been recorded by NOAA tide gauges for many years, and more recent observations have been collected by NASA satellites. The steady rise in sea levels has been attributed to both a warming expansion of the oceans and contributions from melting glaciers and land-based ice sheets. Climate modeling combined with these direct observations suggest sea level rise will continue well into the future with significant implications for California’s coastal communities. During extreme high tide events, we can get an idea of what a permanent rise in sea level might look like in our communities.