The flakes follow the heating, not the calendar. When radiators and forced air run for months, indoor humidity drops sharply, and a cat's skin loses moisture to the room around the clock — while she sleeps, while she grooms, while she sits in her favourite warm spot, which is often directly beside the heat source drying her out. Skin that is dry sheds its surface cells in visible quantities, and a cat's coat, especially a dense winter one, holds those cells against the fur instead of letting them fall away. Part the coat on her back and the flakes sit there in rows, most obvious on dark fur, like dust that was there all along waiting to be disturbed.
Why some cats show it and others do not
A supple, fastidious cat clears much of her own shed skin by grooming, spreading the oils her skin produces along each hair shaft as she goes. Winter exposes the cats who cannot quite keep up: older cats and stiff cats who no longer twist easily to reach their backs, heavier cats whose reach is limited, and any cat whose grooming simply slackens in the cold months. Those cats are not unwell by default; they are under-assisted. The flakes concentrate exactly where the tongue cannot reach, along the spine and over the hips, which is a distribution your own brushing can correct.
Home care that addresses the dryness
Brush her every other day through the heating season, with unhurried strokes that reach the skin and travel the full length of the coat. Brushing does three jobs at once here: it lifts trapped flakes out so they leave on the brush instead of onto your furniture, it spreads her natural skin oils along the fur, which is the coat's own conditioning system, and it shows you the skin underneath, week by week, so you would notice if calm dry skin ever changed into something else.
Support the brushing from the room's side as well. Fresh drinking water in more than one room encourages a cat who drinks opportunistically, and a humidifier running near where she sleeps returns some moisture to the air she spends most hours breathing; owners often see flakes ease within a couple of weeks when the sleeping area stops being the driest spot in the house. Resist the intuitive extra bath. Washing a dry winter coat strips the oils you are trying to redistribute, and a cat bathed more often through winter commonly looks flakier a few days after each bath, not less — the opposite of the result the bath was meant to produce.
Her food already does quiet work here, provided it is a complete diet fed consistently; coat condition is built from nutrition over weeks, not from any single meal. Supplements are a conversation for her vet rather than a shelf decision, because the right question is whether her diet leaves any gap at all — and a complete diet, fed consistently, rarely does.
Flakes that are not about winter
Dry-air flakes sit loose, the skin beneath looks pale and calm, and the cat is unbothered. Flakes accompanied by itching, scratching, scabs, hair coming away in patches, a greasy or strong-smelling coat, or flakes that appear to move deserve a vet visit instead, because parasites, fungal infection, allergies and other skin or internal conditions are among the possibilities a vet would investigate, and none of them resolves with more brushing. The same applies if generous home care through several weeks of every-other-day brushing changes nothing: a problem that ignores its supposed cause is telling you the cause was wrong.
When flakes return after a quiet week, reviewing which brushing sessions were actually completed in the KinsLe app, where the rota lives in Care Teams, reveals whether the routine slipped.