The Role of Chlorine in Seasonal Skin Dryness
Most people notice dry skin creeping in once the weather turns and reach for a heavier moisturiser – a natural response to cold air and indoor heating. But there's a second factor impacting your skin every time you wash, one that doesn't change with the seasons at all: the chlorine already in your shower water. It's not new in winter; what the season changes is how much your skin can absorb it.
Chlorine is in your water on purpose
Before getting into what it does to skin, it's worth knowing why it's there. Water utilities add chlorine to keep water safe from bacteria and other pathogens as it travels from the treatment plant to your tap. The EPA sets a maximum allowed level, 4.0 mg/L, known as the Maximum Residual Disinfectant Level, and most utilities maintain a residual within that limit specifically so the water stays protected the whole way to your home.
That's actually a good thing for drinking water safety. It's also why chlorine is one of the most consistent things reaching your skin in the shower, at a much lower concentration than a swimming pool, but daily, for however long you've been showering in it.
What chlorine actually does to your skin barrier
Skin holds onto moisture using a thin layer of natural oils and lipids on its surface. Chlorine is a mild oxidiser, which is exactly what makes it effective against bacteria, and that same property lets it strip some of that protective layer with repeated contact.
Most of the direct research on this comes from swimming, where exposure is more concentrated. The American Academy of Dermatology notes that "chemicals used to disinfect swimming pools can irritate the skin" and that "pool chemicals can dry the skin." Cleveland Clinic dermatologist Dr. John Anthony makes the same point about eczema-prone skin specifically: "chlorine in swimming pool water… can be irritating to eczema-prone skin." Both organisations recommend rinsing off promptly and moisturising on damp skin afterward.
Obviously a shower delivers far less chlorine contact than a pool session. But the underlying chemistry doesn't switch off at the tap; it's a smaller, more cumulative version of the same exposure.
Why the same exposure feels worse once the weather turns
In the Winter our skin isn't dealing with chlorine in isolation. Dr. Anthony also points out that "cold air, wind and a decrease in humidity can all dry out skin," and that indoor heating drops humidity further still. On top of that, showers tend to run hotter and longer once it's cold outside, and it's the hot water that strips protective oils from skin faster than warm water does (we go into that habit in more detail in Fall Shower Habits That Can Dry Out Your Skin).
None of these are new pressures on their own. What changes in winter is that skin has less reserve to begin with, so the chlorine exposure it barely registered in July starts to show up as tightness, flaking, or irritation in December. It's not that chlorine gets stronger in winter, but more that it's just another thing landing on a barrier that's already stretched thin.
Signs worth paying attention to
Cold-air dryness tends to be general, a whole-body tightness that builds gradually through the day. A few patterns are worth a second look if you notice them specifically after showering:
Tightness or flaking that shows up right after a shower, rather than building slowly over the day, points more toward what's touching your skin in that moment than the room around you.
A newly flaky or itchy scalp, especially if the rest of your skin feels fine, since scalp skin gets direct, sustained water contact, in a way drier winter air alone doesn't explain as well.
Irritation is limited to areas the water reaches, rather than exposed skin like hands and face, which cold air affects most.
None of these confirm chlorine is the cause on their own, and they're not a substitute for seeing a dermatologist if you're managing a flare. They're just a different pattern worth noticing.
What really helps
Keep it warm, not hot, and shorter – we've covered the habit side of it in detail in the fall shower post linked above.
Moisturise on damp skin, within a few minutes of getting out, while the water is still on your skin rather than after it's already evaporated.
Reduce how much chlorine reaches your skin in the first place. This is where filtration comes in. Our SF400 Daily Revitalize+ Shower Filter uses calcium sulfite, redox media and activated carbon to reduce chlorine, with 40% more active filtration medium and double the Vitamin C of our entry-level filter. It's designed for sensitive skin and formulated with eczema-prone skin in mind, which makes it the one we'd point to first when winter is compounding things.
If you want the same fundamentals in a simpler, lower-cost option, the SF100 Daily Revitalize Vitamin C Shower Filter reduces chlorine and infuses Vitamin C in the same way. And if you're on well water, the SF220 Daily Essential Shower Filter is the one built for that.
A filter won't undo cold air or a hot shower habit on its own. It reduces one part of what's working against your skin, alongside warmer water and a moisturiser that's actually reaching damp skin.
SF400 Daily Revitalize+ Shower Filter
Sale price
$38.99
Frequently asked questions
Is dry winter skin really about chlorine, or is that overstating it?
Cold air and lower humidity are the bigger, more immediate cause. Chlorine is a smaller, steadier factor that's present all year, it just becomes more noticeable once your skin has less reserve to absorb it.
Is shower water as harsh on skin as pool water?
No. Pool chlorine is maintained at a higher, more concentrated level specifically to disinfect standing water that many people share. Shower water carries far less, but research on household tap water has still found a measurable link to skin irritation, so it isn't a non-factor either.
Will a shower filter stop winter dryness completely?
No, and we wouldn't want to suggest it does. It reduces chlorine reaching your skin, which may help reduce irritation, but it works alongside warmer water, shorter showers and moisturiser, not instead of them.
Should I switch to cold showers in winter to avoid the hot water problem?
Not necessarily. Dermatology guidance points to warm, not hot, not cold, as the better middle ground for skin during colder months.
