Ocean tides result from the gravitational interaction and the ever-changing geometry between the sun, moon and Earth. Although high tides and low tides happen daily, extra large spring tides take place at the vicinity of new moon and full moon. Neap tides, which happen around first quarter moon and last quarter moon, display the minimal variation between high and low tide. These tide almanacs are based upon the relatively straightforward astronomical influences on the tides, not the hard-to-predict meteorological factors, such as barometric pressure and wind.

Tidal Predictions by the National Ocean Service

WWW Tidal and Current Predictor by the University of South Carolina

Tide predictions around the globe by Tides.INFO

UK and Irish Tidal Predictions

XTide Tide Prediction Server

This beautiful image is from EarthSky Facebook friend John Lloyd Griffith

Bottom line: The tide almanacs recommended here are based on astronomical influences on the tides. They can help you know when to expect high and low tides.

Bruce McClure

Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.