Tide Database

A public database of tide harmonics

This database includes harmonic constituents for tide prediction from various sources around the world. These constants can be used with a tide harmonic calculator like Slackwater to perform tide predictions.

Every station with a published page is on slackwater.xyz, and the Slackwater app for iPhone predicts tides from this database.

10049

Stations

129

Countries

359

Constituents

100%

Open Data

Data Sources

NOAA

Primary source for US coastal stations. Harmonic constituents derived from years of continuous water level observations at NOAA tide gauge stations.

TICON-4

TIdal CONstants based on GESLA-4 sea-level records contains 50 estimated tidal constituents from 4200+ tide gauges distributed globally.

Access the Database

GitHub Repository

Browse the full database, make improvements, or add new sources through our GitHub repository.

View on GitHub

Direct Download

Download the complete database as JSON or CSV files for offline use or integration into your own applications.

Download Data

Station Pages

Tide and current predictions for each station, organized by country and region, on slackwater.xyz.

Browse Stations

API Access

Query stations and retrieve harmonic data programmatically through our RESTful API.

View API Docs

Contribute to the Database

Help improve the tide database by contributing station data, corrections, or enhancements. All contributions are welcome!

Contribute on GitHub