A female cat is in heat several times a year, and the exact length of this period depends on the cat’s breeding cycle. Outdoor cats are more likely to go into heat from spring to fall, when the daylight hours are longer and the reproductive hormones of the queen begin to be stimulated. If a cat is not spayed, it may continue to go into heat for a few weeks or even months.
The estrus cycle in a female cat lasts between 14 and 21 days. During this time, she will repeatedly breed, ovulating as many times as every four to seven hours. During her breeding season, she will have multiple heat cycles. During these periods, cats will be extremely affectionate, raise their rear legs when being stroked, and become very vocal. These behavior changes can be confusing for the cat owner.
In some cats, the duration of the estrous cycle is as short as three days, but the exact time varies. This is usually not the case with unspayed female cats, who will remain in heat for up to six weeks. Once the estrous cycle ends, the female cat will return to her usual self. A spayed cat will not stay in heat for more than a few days during her first estrous cycle.

How long does estrus last?
Estrous lasts about two weeks. The average estrous cycle is 14-21 days. In most cases, the estrous cycle starts at least once a month, but it may start as often as twice a week. However, if you notice that your cat has been going into heat for an unusually long time, consult your veterinarian.
What causes heat?
Heat is caused by the release of estrogen and progesterone by the ovaries. Estrogen stimulates the uterus to contract, while progesterone helps prepare the lining of the uterus for fertilization. Both hormones are produced by the ovaries.
During the estrous cycle, the amount of estrogen increases gradually until it reaches its peak level just before ovulation. At this point, the follicles containing eggs mature and rupture, releasing the egg cells. Progesterone levels also increase slightly, preparing the uterine lining for implantation.
What Happens When Cats Go into Heat?
Cats go into heat when the female’s uterus lining becomes thick. The female will give off pheromones to attract males in the vicinity. The female cats are in heat for about 5 to 7 days in a row, and all they want is to mate.
The average length of a single heat cycle is about one week, but it can last as long as two weeks. After that, the cat will return to her normal habits, and it will repeat the cycle for about two to three weeks. A female cat will continue to be in heat until it is spayed or neutered. During her first estrus cycle, a female cat will be very affectionate, and may spray a strong-smelling urine in an effort to attract male cats.
A female cat’s cycle can last as long as three weeks. The cat may be in heat for up to three weeks. It may also be dependent on the breed of the cat. A Persian cat will typically stay in heat all year. A short-haired female will remain in heat for four to six weeks. During the winter, Persians will cease to go into the mating phase. They usually go into the estrus only once, but some breeds remain in heat for more than six days.
Depending on the breed, a female cat’s first heat or estrus occurs at about eighteen months of age. If she is not pregnant, she will be in interestrus for about four weeks. If she has not yet given birth to a kitten, she may start displaying pregnancy indicators before her first heat. It may even exhibit some signs of pregnancies. But if she hasn’t borne any children, the timeframe for the next period can range from four to 21 weeks.
As mentioned above, cats can be’silent callers’. In other words, they do not show any external signs. They will be in estrus again in a few days, and again during the summer. A female cat may become destructive or impatient during this time. A’silent caller’ will no longer act out her mating signals. So, a cat in heat will start rubbing her neck and head against objects.
A female cat will have up to six heat cycles per year. The first heat cycle will last for about two weeks. During the resting phase, a cat will not mate. The second is called interestrus. This is the time for a female to be fertile. During her heat cycle, she will be more active and less likely to sleep. While this may sound scary for the owner, it is normal to feel nervous about her cat.
It is important to understand that female cats can only be in heat if they have a male cat. If the female cat is already mated, it will not go into heat again. During her heat phase, she may roam around the grounds looking for the next potential mate. A cat in this state can be pregnant, so you should make sure it isn’t left alone. If it doesn’t mate, it can even re-enter the cycle.