If you spend a lot of time around cats, then you're likely very familiar with the pure frustration and "yuck factor" of urine spraying, no matter how much you may love them. Unfortunately, a tomcat's spraying behavior probably won't stop along with the end of a queen's heat cycle.
When female cats are in heat, one of their common behaviors is urine spraying. Queen cats do this as a way to notify nearby males of their mating availability. If a tomcat picks up on the smell of the urine, it may "activate" him to go after her, whether simply by chasing or by spraying his chemical scent for her to detect, too. Once a female's heat cycle is completed -- after approximately 10 days or so -- the male will no longer smell her urine, and may as a result stop spraying for a while, but definitely not necessarily.
Other Female Cats
A male cat's hormones are not driven by the presence of just one single female cat. The little guys are players. Even if one queen is now out of heat, that doesn't mean that there aren't countless other nearby queens that will soon be going into season. For example, your tomcat may enjoy his daily ritual of sitting on a window perch looking at the other animals outside. If he notices a new stray female cat walking by, that could also trigger him to spray again. When a male cat is reproductively mature and unfixed, it isn't really possible to get a handle on his hormonal urges.
Even without the presence of female cats, other factors can encourage urine spraying in tomcats. For instance, anxiety and stress are both major culprits in feline urine marking behavior, whether a lot of fighting is going on or the household is packing for a major cross-country move. Competition and territorial behaviors also can bring upon spraying. If you just adopted a new younger cat into your home, your older resident male cat may just take up an annoying spraying habit to show the newbie his higher-up status -- and also to tell him to back down, or else.
One of the most effective ways to reduce urine spraying in a male cat is by getting him neutered. Even neutering a cat isn't a 100 percent surefire solution, but thankfully, if you give a male cat some time, fixing usually eliminates or at least greatly minimizes the pungent and persistent habit. Not only will you probably prevent yourself from having to deal with the headache of cleaning up urine patches throughout your home, you will help keep feline overpopulation in your area more manageable, especially if your male cat goes outdoors a lot -- nice.