By David Cavalier – Updated Mar 24, 2022
A mixed tide is a tidal pattern that features two high tides and two low tides of differing magnitudes within each 24‑hour and 50‑minute cycle. Unlike a semidiurnal tide—where the two highs and two lows are roughly equal—a mixed tide presents a high‑high, high‑low, low‑high, and low‑low sequence.
Earth’s tides are primarily driven by the Moon’s gravity, with the Sun’s pull adding a secondary effect. The closer the Moon is to Earth, the larger the tidal range, and the same principle applies to the Sun, though its influence is comparatively weaker.
Mixed tides arise in regions where diurnal (one high and one low per cycle) and semidiurnal patterns combine. This interaction produces uneven high and low tides, creating the distinctive rhythm that surfers on the U.S. West Coast and in Mexico adore.
These tides are the second most frequent global tide type, found along the West Coast of the United States and Mexico, as well as in the Caribbean Sea and Arabian Sea. Accurate tide charts are essential for navigation and recreation in these areas.
