Tides

Tide predictions for thousands of stations worldwide, powered by open source software and open data.

Understanding Tide Predictions

Tide predictions are calculated using harmonic analysis, a method that breaks down the complex tidal signal into a series of simple wave components called harmonic constituents. Each constituent represents the effect of a specific astronomical or oceanographic force on the tides.

Our predictions are based on harmonic constituents derived from historical tide observations at reference stations, and offsets for subordinate stations that are referenced to nearby primary stations.

Learn more about harmonic constituents

Data Sources

Our tide database incorporates data from multiple authoritative sources:

  • NOAA CO-OPS: Harmonic constituents for US coastal stations from the National Oceanic and Atmospheric Administration
  • IHO TICON: International tide constituent database from the International Hydrographic Organization
  • Community Contributions: Additional stations and data contributed by the marine community

Start Exploring Tides

Find tide predictions for your favorite locations or integrate our API into your application.