Why your cat sheds more in spring
Some time around March you will notice that the black jumper is no longer black, that there is a drift of fur behind the sofa, and that your cat appears to be producing more of itself than physics allows.
This is normal, it is temporary, and there is a specific reason it happens when it does.
Cats have two coats, not one
The top layer is guard hair: long, coarse, and responsible for how your cat looks. Underneath sits the undercoat, which is short, dense and soft, and does the actual work of keeping temperature stable.
Guard hairs turn over slowly all year. The undercoat does not. It comes in thick for winter and then releases in bulk when the season turns, which is why shedding arrives as an event rather than a trend.
It is light, not temperature
This is the part that surprises people. The trigger is day length, not warmth. Photoreceptors register the change in daylight hours, and that signal drives the coat cycle.
Which means your thermostat has nothing to do with it, and it explains the thing that frustrates indoor cat owners most.
Why indoor cats shed all year
An indoor cat lives under artificial light on a schedule that barely changes between December and June. The seasonal signal arrives muddled, so instead of two clean sheds a year, the coat turns over in a low, constant trickle that never quite stops.
The total amount of fur is roughly the same. It is just spread across twelve months instead of concentrated into a few weeks, so there is never a period where the sofa recovers.
Cats with more window access tend to shed in clearer seasonal waves. Cats in flats with little natural light shed steadily and forever. Neither is a health problem.
What actually reduces what lands on your furniture
Nothing stops shedding. The hair is coming out either way. The only variable you control is where it goes.
Brush more often, for less time. Two short sessions a week move far more undercoat than one long monthly effort, and they do not exhaust your cat's patience. Consistency beats duration by a wide margin here.
Capture at the source. A brush loosens hair. Whether it then lands on the floor or gets collected is a separate question. This is the entire argument for a grooming vacuum: the hair goes from the coat into a sealed canister without an airborne stage in between.
Damp beats dry. Damp fur does not float. A light mist as you brush keeps loose hair on the teeth of the comb instead of drifting off to settle somewhere you will find it in August.
Check the food. Coat quality tracks protein and fatty acid intake closely. A cat on a poor diet sheds more, and the fur is duller and breaks more easily. This is the slowest lever but it is real.
When shedding is worth a vet visit
Seasonal shedding is even. The coat thins overall, and the cat is otherwise themselves.
Worth a call to your vet instead: bald patches or thinning in one specific area; visible skin underneath, or skin that is red, flaky or scabbed; a sudden change in how much your cat grooms themselves, in either direction; fur that comes out in clumps when you barely touch it; or shedding alongside weight loss, appetite change or lethargy.
Overgrooming from stress or allergy looks like shedding from a distance and is a completely different problem. If the fur is going missing in a pattern rather than everywhere, that is the one to have looked at.
The realistic expectation
A cat that sheds heavily will still shed heavily. What good grooming changes is the destination. Twenty minutes a week is the difference between fur in a canister and fur in your coffee, and that is genuinely the whole of it.