Tide Window Calendar

Find predicted high and low tides at ten NOAA stations, filter by height and local time, and export planning windows around matching events.

Starts with an editable example. Replace the dates and rules with your own.

Your calculation

Ready when you are

Choose your dates.

Select your counting rules and calculate.

How to use this calculator

Choose a station, up to 31 local dates, units, tide type and optional height/time filters. Select how many minutes to reserve around an event.

Fetches NOAA CO-OPS predictions directly when you calculate. Heights use Mean Lower Low Water (MLLW); display uses the station's local time zone. Planning windows do not guarantee a threshold height throughout the interval.

A worked example

Choose San Francisco and low tides, then filter events below your selected MLLW height. A 30-minute buffer creates a one-hour planning window around each match.

Are these observations or navigation guidance?

They are astronomical predictions, not observed water levels or weather-adjusted forecasts. Use official local guidance for navigation and water safety.

Further reading: NOAA CO-OPS prediction API. Your entered rules determine this result.

Which calendar and years are supported?

Gregorian input coverage is 1900-2100 unless the method states a narrower range. Results explain calendar conventions and local date boundaries. Astronomy uses a level horizon at sea level. CSV, print and copy retain the result rules; calendar files contain only calculated events. Nothing is scheduled automatically.

What happens to my dates?

Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.

Loading tide predictions sends the selected station, date range and units directly to NOAA. A connection is required; predictions are fetched again each time you calculate.