Perigean Spring Tides—often called "King Tides" —are the year's highest and lowest tides, resulting in the largest tidal range. They occur when two major astronomical effects align:

1. Spring Tide: The Sun, Moon, and Earth are nearly in a straight line (during a New or Full Moon), combining their gravitational pull to create higher-than-average tides.

2. Perigee: The Moon is simultaneously at its closest point to Earth in its monthly elliptical orbit, maximizing its gravitational influence.

This powerful combination, which happens a few times a year, can lead to exceptionally high water evels and coastal flooding, especially when combined with high winds or low atmospheric pressure. The term "spring" here does not refer to the season but to the water "springing forth.