Our data

Everything on your Tidesy comes from public sources, most of them US government agencies. Here's where each piece comes from, how fresh it is, and how it looks on the screen.

Tides and water

From NOAA, the agency that publishes the official US tide tables.

• Tide predictions

  The tide curve, highs and lows, and where the water is right now. Each station's predictions come from NOAA's own tide model for that exact spot. Which stations we use, and why.

  Source NOAAFreshness The whole day is loaded each night after midnight
  

• Live water level

  At stations with a working tide gauge, the water level actually measured at the station, drawn as blue dots on top of the predicted tide, with how far it's running above or below. NOAA marks the newest readings as preliminary until they've been checked.

  Source NOAA tide gaugesFreshness Every 6 minutes
  

• Flood levels

  NOAA's official flood level for your station, drawn as a red dashed line, so you can see how close the water is getting.

  Source NOAAFreshness Loaded once for each station; these rarely change
  

• Water temperature

  Measured at the station, where NOAA has a temperature sensor. It appears in the conditions box and the line under the station name.

  Source NOAAFreshness About once an hour
  

Weather and ocean

From Open-Meteo, which brings together forecast models from national weather services, including NOAA. We use their commercial service.

• Current weather

  Temperature, wind speed and wind direction at your station, on the line under the station name.

  Source Open-MeteoFreshness Every few minutes
  

• Rain forecast

  Hour-by-hour rain for the day, in a strip under the tide curve.

  Source Open-MeteoFreshness About once an hour
  

• Waves

  Wave height for the water near your station: the current value, and hour by hour under the tide curve.

  Source Open-Meteo marine forecastFreshness About once an hour
  

• UV and air quality

  UV index and air quality, now and hour by hour, in their standard colors. The air quality data comes from the European Union's Copernicus Atmosphere Monitoring Service.

  Source Open-Meteo, CopernicusFreshness About once an hour
  

Alerts

• Weather alerts

  Warnings, watches and advisories for your station, from small craft advisories to coastal flood warnings. They appear as bars across the hours they cover and as full-text pages, the same alerts you'd see on weather.gov.

  Source National Weather ServiceFreshness Every few minutes
  

Sun and moon

• Sunrise, sunset and moon phase

  Daylight hours as a bar along the bottom, with sunrise, sunset, moonrise and moonset marked on the timeline, for your station's location and time zone.

  Source US Naval ObservatoryFreshness Once a day
  

Extras

These appear when you turn them on.

• Razor clam digs and closures

  Upcoming razor clam dig days for Washington beaches, and shellfish closures for Washington, Oregon and California.

  Sources Washington Department of Fish & Wildlife, Oregon Department of Agriculture, California Department of Public HealthFreshness Once a day

• Weather radar and maps

  On your Tidesy's web dashboard, a map of your stations with a live radar layer you can turn on to watch storms approach.

  Sources NOAA NEXRAD radar via Iowa State University; maps by OpenStreetMap contributorsFreshness Radar every 5 minutes
  

Good to know