Your skin does not get drier in winter. The air does, and it takes the difference out of you.
Every year, within about a fortnight of the heating going on, the same thing happens: skin that was perfectly comfortable through summer starts feeling tight after showers, shins get flaky, and hands crack around the knuckles. Almost nobody connects it to the thermostat.
Here is what is actually happening, and a month-by-month view of what to change.
The humidity problem
Relative humidity is how much water vapour air holds compared with the maximum it could hold at that temperature. Warm air can hold considerably more than cold air.
So when cold winter air — already carrying little moisture — comes indoors and gets heated to 20°C, its relative humidity drops sharply. In a heated British home, indoor relative humidity commonly falls from around 50% in summer to nearer 30% in midwinter.
Air below about 40% relative humidity behaves like a sponge. It draws moisture from whatever it touches, including you, continuously, at a rate your skin was not built to keep up with. This is the same physics that dries out houseplants and warps wooden furniture in winter. Skin is simply another surface losing water to thirsty air.
Why your summer routine stops working
A light lotion works well in July for a reason: it is mostly water, held in emulsion, and in humid air that water has somewhere to go and time to be useful.
In 30% humidity, the same product behaves differently. The water fraction evaporates quickly, and because evaporation is a cooling, drawing process, it can take some of your own surface moisture with it. You apply a moisturiser and your skin feels tighter forty minutes later. That is not your imagination.
What winter calls for is a higher proportion of lipid — something that forms a barrier and stays put rather than evaporating. Raw shea butter is around 40 to 48% stearic acid, which is solid at room temperature and does exactly that job. We whip ours with avocado and sweet almond oil so it spreads like a cream instead of sitting on top like a wax; you can read the full fatty acid breakdown here.
The change that matters most
If you do one thing from this page, do this: apply moisturiser within about three minutes of getting out of the shower, while your skin is still slightly damp.
No moisturiser adds water to skin. What an occlusive does is slow the rate at which water leaves. Applied over damp skin, it traps water that is already there. Applied to fully dry skin an hour later, it seals in whatever is left, which by then is considerably less.
Same product, same amount, markedly different result. It costs nothing and most people have never been told.
A seasonal calendar
October: change before you need to
The heating goes on and the damage starts before the symptoms do. Switch to a richer moisturiser now rather than in November when your skin is already complaining — it is much easier to maintain a barrier than to rebuild one. Move to lukewarm showers while the change still feels tolerable.
November: fix the shower
This is when most people notice. Hot water strips surface lipids faster than warm water does, and a long hot shower on cold-feeling skin is the single most counterproductive thing available. Lukewarm, under ten minutes, and a cream or oil-based wash instead of a foaming gel on the areas that feel dry.
December: hands and the bits you forget
Hands take the worst of it — washed constantly, exposed to cold air, rarely moisturised properly. Shins, elbows and the tops of feet are close behind, all areas with fewer oil glands. Keep a jar where you will actually use it rather than where it looks tidy.
January: address the air itself
The coldest, driest stretch. A humidifier in the bedroom does more than anything you apply, because you spend eight unbroken hours there. Aim for 40 to 50% relative humidity; a cheap hygrometer tells you where you are. Drying laundry indoors achieves something similar, if less precisely.
February: check what you are wearing and washing with
Wool jumpers and biological detergent residue both irritate skin that is already compromised. If itching has crept in over the winter, switch to non-biological detergent and run an extra rinse for a fortnight to see whether it helps.
March: don't stop early
The heating stays on well past the first warm week, and skin recovering from four months of dry air takes time. Keep the richer routine going until the heating is genuinely off for good.
What not to bother with
A few things get recommended every winter and do very little.
- Drinking more water. Hydration matters for health, but in someone already adequately hydrated, extra water does not measurably change skin moisture. The problem is barrier function and evaporation, not supply.
- A bowl of water on the radiator. The surface area is far too small to shift the humidity of a room meaningfully.
- Very hot baths to warm up. Pleasant, and actively counterproductive.
- Exfoliating more because skin looks flaky. The flaking is a barrier problem. Removing more of the barrier does not solve it.
If it goes beyond dryness
Winter dryness that itches persistently, cracks, weeps or does not respond to several weeks of sensible care is worth raising with a GP or pharmacist rather than working through by trial and error. We go through the warning signs in more detail in Dry, Itchy Skin: Why It Happens and What Actually Helps. A moisturiser is a cosmetic product, not a treatment.
Frequently asked questions
Why is my skin so dry in winter?
Cold outdoor air holds little moisture, and heating it indoors drops relative humidity further — commonly from around 50% in summer to nearer 30% in a heated home. Dry air draws water from skin continuously, faster than the barrier can replace it.
Does central heating dry out your skin?
Indirectly, yes. Heating does not remove moisture from skin itself; it lowers the relative humidity of indoor air, and that dry air then draws moisture from any surface it contacts, skin included.
Should I change my moisturiser in winter?
Usually yes, towards something with a higher lipid content. Water-heavy lotions evaporate quickly in dry air, while a butter or ointment forms a barrier that slows water loss for longer.
What humidity level is best for skin?
Around 40 to 50% relative humidity is generally considered comfortable. Below roughly 40%, air draws moisture from skin noticeably faster. An inexpensive hygrometer will tell you where your home sits.
Does drinking more water help dry winter skin?
For someone already adequately hydrated, not measurably. Winter dryness is a barrier and evaporation problem rather than a supply one, so what you apply and when matters more than what you drink.
