Ocean tides are driven by the gravitational effects of the Moon and Sun. They appear along coastlines as a recurring rise and fall in sea level. High tide and low tide are the upper and lower parts of that cycle.
Think beyond the waves at your feet
NOAA describes tides as very long-period waves moving through the ocean. The difference in water height between high and low tide is called the tidal range.
A breaking wave in front of you and a tide changing the background water level are not interchangeable ideas. When you compare two beach photographs, asking whether they were taken at different tide stages can be more useful than asking which day had bigger surf.
Spring tides are not a springtime event
According to NOAA’s spring and neap tide explainer, tidal ranges are generally larger around new and full Moon, when the Sun, Earth and Moon are roughly aligned. These are spring tides, and they occur throughout the year.
Near the first and third quarter phases, the Sun and Moon lie at right angles as viewed from Earth. Their effects partly counteract one another, producing the smaller ranges called neap tides. The labels describe a pattern in tidal range, not a guarantee about the water height at a particular beach.
Read a local prediction, not a generic rule
For a place-specific look, start with an official tide station near the location you are interested in. NOAA links to its tides and currents service from the explanation above. Check the station name, date, time convention and height units before comparing entries.
As a reading exercise, put one predicted high and one predicted low from the same station on a simple timeline. Keep the units beside the numbers. Do not mix a value from one harbor with another and call the difference a change through time.
This exercise is for understanding the table, not planning safe access across a tidal route. Use current local guidance for real coastal activities.
Next, understand the Moon’s phases or the distinction between weather and climate.
