---
title: "Tide predictions - high/low and water levels (NOAA CO-OPS)"
method: GET
path: "/api/v2/transport/tides"
tags: ["Transportation"]
---

# Tide predictions - high/low and water levels (NOAA CO-OPS)

`GET /api/v2/transport/tides`

Astronomical tide predictions (high/low extremes, or hourly / 6-minute water levels) for a US NOAA CO-OPS station - by station id, or by the nearest station to a coordinate. Harmonic PREDICTIONS, not measured levels and not real-time; NOT of navigational class. US stations only.

## Query parameters

- `station` string, nullable — NOAA CO-OPS station id (7 digits), e.g. 8443970 (Boston).
- `lat` number, nullable — Latitude - resolve the nearest tide-prediction station (with lon).
- `lon` number, nullable — Longitude - resolve the nearest tide-prediction station (with lat).
- `date` string, nullable — Window start, YYYY-MM-DD (GMT); default today.
- `days` integer — Window length in days from the start date.
- `interval` 'hilo' | 'hourly' | '6min' — hilo (high/low extremes) | hourly | 6min (native step).
- `datum` string — Tidal datum: MLLW | MSL | MHW | MLW | MHHW | MTL | NAVD | STND.
- `units` 'metric' | 'english' — metric (metres) | english (feet).

## Response `200`

Successful Response

- EnvelopeTidesFeed
  - `data` TidesFeed, required
    - `query` TidesQuery, required
      - `station` string, nullable
      - `lat` number, nullable
      - `lon` number, nullable
      - `date` string, required — Window start (YYYY-MM-DD, GMT).
      - `days` integer, required
      - `interval` string, required — hilo | hourly | 6min.
      - `datum` string, required
      - `units` string, required
    - `station` TideStation, required
      - `id` string, required — NOAA CO-OPS station id.
      - `name` string, nullable
      - `state` string, nullable
      - `lat` number, required
      - `lon` number, required
      - `distance_km` number, nullable — Distance from the requested lat/lon; null when a station id was given directly.
    - `interval` string, required
    - `datum` string, required
    - `units` string, required — metric (metres) | english (feet).
    - `count` integer, required
    - `predictions` TidePrediction[], required
      - `time` string, required — Prediction time, GMT (YYYY-MM-DD HH:MM).
      - `value` number, nullable — Predicted water level, in the requested units (metres or feet), relative to the datum.
      - `type` string, nullable — H (high) or L (low) for interval=hilo; null for hourly / 6-minute levels.
  - `meta` SugraMeta, required — Metadata attached to every /api/v1/* response envelope.
    - `endpoint` string, required — Requested endpoint path.
    - `data_time` string, required — ISO 8601 UTC timestamp of the source data, not of the request.
    - `response_time` string, required — ISO 8601 UTC timestamp when this response was produced.
    - `provider` string, required — API name and version.
    - `source` string, nullable — Identifier of the primary upstream source used for this response.
    - `attribution` string, nullable — Human-readable attribution mandated by an upstream source (e.g. a securities regulator or self-regulatory organization). Present only on responses whose source requires the owner and source to be clearly identified. Do not remove or alter it when using the response.
    - `fallback_used` boolean, nullable — True when the primary source failed and a fallback produced the data.
    - `fallback_chain` string[], nullable — Ordered list of sources attempted, in the order they were tried.
    - `cached` boolean, nullable — True when this response was served from the internal cache.
    - `stale` boolean, nullable — True when the cached response was returned after the upstream rate-limited or errored. Clients can use this to detect degraded data.

## Other responses

- `401` — Missing or invalid `x-api-key` header.
- `422` — Validation Error
- `429` — Daily rate limit exceeded. Check `X-RateLimit-Reset` for the next window.
- `503` — Upstream source is temporarily unavailable. Retry after a short delay.

---

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