Topic summary
Spring tide
Extracted from the Wikipedia article Tide.
Lunar distance
The changing distance separating the Moon and Earth also affects tide heights. When the Moon is closest, at perigee, the range increases, and when it is at apogee, the range shrinks. Six or eight times a year, perigee coincides with either a new or full moon causing perigean spring tides with the largest tidal range. The difference between the height of a tide at perigean spring tide and the spring tide when the moon is at apogee depends on location but can be as large as a foot higher.