cyclical

Though day-to-day weather changes are unpredictable, nature’s seasons can always be counted on to move in cyclical or predictable patterns.

Cyclical is used to describe things that are regularly patterned or that occur in regular intervals. The root of cyclical is “cycle” which means movement in a circular fashion, or the circular fashion itself. Planets orbit the sun in cyclical patterns, the moon’s phases are cyclical as well. Some stock brokers say that the market is cyclical, but that may be just a way of telling people to keep investing when it's down.