The University of Hawaii Sea Grant College Program's Hawaii and Pacific Islands King Tides Project documents high water level events known as King Tides to better understand future impacts from sea level rise and other coastal hazards. King Tides provide a window into the future because today's high tides are predicted to become tomorrow's average sea levels. Citizen scientists have contributed to this free, publicly-accessible, and crowd-sourced dataset by photographing King Tides at places important to them throughout Hawaii and Oceania. Photos, observations, date, time, location, and other metadata are submitted online. This publicly-accessible online database informs research, policy, and decision making across the State of Hawaii and the wider Pacific region.

King tides are the highest astronomical tides of the year. The scientific term for a King Tide is a perigean spring tide. King Tides in the Hawaiian Islands tend to occur during the summer (e.g., July and August) and winter months (e.g., December and January) in conjunction with new moons and full moons. King Tides, or the highest high tides of the year, are a unique coastal hazard. The timing of these extreme water level events can be anticipated through the use of tidal predictions, yet their impacts (e.g., coastal flooding and inundation in low-lying areas) can have devastating consequences for coastal inhabitants, particularly when combined with severe weather or high wave events. It is a common misconception that King Tides are the result of man-made climate change. When in reality, they are not byproducts of climate change, rather they are windows for us to see what the future of sea level rise from global climate change might look like along our coastlines. With future sea level rise we can expect more frequent high tide flooding and monthly and even daily high tides exceeding coastal inundation thresholds.

When sharing these photographs, please cite this project with the following attribution:

(c) Hawaii Sea Grant King Tides Project, (year of photo). Some rights reserved. Licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).