Cats typically start going into heat between 5 to 9 months of age, although some kittens can start as early as 3 to 4 months, and others may not experience their first heat until around 18 months. The age when a cat goes into heat depends on breed, weight, and environmental factors such as time of year and light exposure. Cats are seasonal breeders and their heat cycles usually begin in the spring and occur repeatedly every few weeks if they do not mate. During heat, cats exhibit behavioral changes such as increased vocalization, affection, restlessness, and a mating posture. Unspayed female cats will continue to go into heat annually until they are spayed.
