Extreme Water Levels

Created: 7/31/2017 - Updated: 2/27/2020


Extreme Water Levels in an online product that allows users to analyze the likelihood that local tides will exceed a given elevation (mean high or low water) at different monthly and yearly time scales. Extreme Water Levels calculates these likelihoods based on over 30 years of monitoring data, and provides viewers with a rough idea of extreme tide heights expected every year, every other year, every 10 years, and every 100 years. Exceedance probabilities can be paired with real-time monitoring to document and determine extreme events, but can also be used for planning purposes to prepare for extreme low- or high-tide scenarios. Data is relevant only for specific NOAA CO-OPS monitoring stations, but a color-coded map allows general comparisons between different U.S. regions and sites.

Phase of Adaptation: Awareness, Assessment, Planning, Monitoring


Land managers, water utility managers, natural resource managers, local authorities, planners, policymakers, engineers, scientists


Contact: NOAA Center for Operational Oceanographic Products and Services


NOAA is an agency that enriches life through science. Our reach goes from the surface of the sun to the depths of the ocean floor as we work to keep citizens informed of the changing environment around them. From daily weather forecasts, severe storm warnings and climate monitoring to fisheries management, coastal restoration and supporting marine commerce, NOAA’s products and services support economic vitality and affect more than one-third of America’s gross domestic product.