The most common tide pattern around the world is that of semi-diurnal tides. This pattern contains two high tides and two low tides of the same height occurring in a 24-hour period. Semi-diurnal tides occur when the moon is over the equator.
Two other tidal patterns are diurnal and mixed tides. Diurnal tides contain one high and low period a day. They occur when the moon is farthest from the equator. A mixed tide is a special type of semi-diurnal tide that exhibits varying heights of each of the high and low tides. Mixed tides occur as the moon transitions either north or south of the equator.