TidesAtlas API

Worldwide tide predictions, marine forecasts and astronomical data for 13,000+ ports in 180 countries.

Base URL: https://tidesatlas.com/api/v1

Documentation: tidesatlas.com/api/docs

Dashboard: tidesatlas.com/api/dashboard

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Features

• Tide predictions for 13,000+ ports across 180 countries
• Tidal coefficients (French coefficient scale, 20-120)
• Weather forecasts — temperature, wind, precipitation, UV index
• Marine data — wave height, swell, wave direction, sea state
• Astronomy — sunrise, sunset, moon phase, illumination
• Multiple datums — LAT, MSL, MLLW, MHW, MHHW, and more
• Real-time observations for French REFMAR stations

Quick start

1. Sign up at tidesatlas.com/api/register (50 free credits, no credit card)
2. Copy your API key from the dashboard
3. Make your first call:

curl -H "X-API-Key: YOUR_KEY" \
  "https://tidesatlas.com/api/v1/tides?port=brest&days=3"

Endpoints

Endpoint	Description
GET /tides	High & low tide times, heights, and coefficients
GET /ports	Search ports by name, coordinates, or country
GET /countries	List all countries with port counts
GET /weather	Weather forecast (1-7 days)
GET /marine	Wave & swell forecast (1-7 days)
GET /astronomy	Sunrise, sunset, moon phase
GET /conditions	Weather + marine + astronomy in one call
GET /history	Historical tide & weather data

Authentication

Pass your API key in the X-API-Key header:

X-API-Key: ta_your_api_key_here

Examples

Full working examples in multiple languages:

• Python
• JavaScript / Node.js
• PHP
• cURL

Response example

{
  "port": {
    "name": "Brest",
    "slug": "brest",
    "country": "France",
    "region": "Brittany"
  },
  "datum": {
    "reference": "LAT",
    "available": ["LAT", "MSL", "MLLW", "MHW", "MLW", "MHHW", "MTL"]
  },
  "extremes": [
    {
      "datetime": "2026-05-13T05:18:00+02:00",
      "height_m": 6.79,
      "type": "high"
    },
    {
      "datetime": "2026-05-13T11:45:00+02:00",
      "height_m": 0.82,
      "type": "low"
    }
  ]
}

Datum conversion

Request heights in any supported reference frame:

# Heights relative to Mean Sea Level
curl -H "X-API-Key: KEY" \
  "https://tidesatlas.com/api/v1/tides?port=brest&datum=MSL"

# Heights relative to Mean Lower Low Water (US standard)
curl -H "X-API-Key: KEY" \
  "https://tidesatlas.com/api/v1/tides?port=seattle&datum=MLLW"

Rate limits

Plan	Requests	Price
Free	50 one-time credits	$0
Hobby	500/day	$4.99/mo
Starter	1,000/day	$9/mo
Pro	10,000/day	$29/mo
Business	50,000/day	$79/mo

Rate limit headers are included in every response:

X-RateLimit-Limit: 500
X-RateLimit-Remaining: 347
X-RateLimit-Reset: 1715644800

Data sources

• Tide predictions: Harmonic analysis using TICON-4 and FES2022 tidal constituents
• Weather: NOAA GFS via Open-Meteo (CC BY 4.0)
• Marine: Copernicus Marine / ECMWF via Open-Meteo (CC BY 4.0)
• Astronomy: Computed from solar/lunar ephemeris

Status

API status page: tidesatlas.com/api/status

Support

• Email: support@tidesatlas.com
• Issues: GitHub Issues

License

This repository contains documentation and example code only. The examples are released under the MIT License. The API itself is a commercial service — see Terms of Use.