Good hair starts with the water.

Water hardness changes how your hair behaves, city by city. Add your cities below and we turn your hair profile into a wash plan for each one.

Build your wash plan

Set your hair profile once, then add your cities. The plan updates as you go.

Your hair, your trip

Texture does most of the work; background, age and routine fine-tune it.

Hair texture
How do you dry it?
Organic products

Pick a city from the suggestions, then tap Add a city. Add stops in the order you visit them, up to 10 cities.

Your plan

CityWater hardnessWashing plan

Season calendar ·

Packing list

    The world water map

    Tap a pin or a city to add it to your trip. Colour shows hardness.

    Soft · under 60 mg/L Moderate · 60–119 Hard · 120–180 Very hard · over 180

    The interactive map could not load here, so use the city list: it carries the same hardness figures.

    Select a city to see its water profile.

    Every city, A to Z

    Search by city or country, or filter by region and hardness band. Tap a city to load its water profile into the planner above.

    All 302 cities · tap to select
    Showing 302 of 302 cities

    How hardness is measured

    One number, three scales. Milligrams per litre (mg/L) is the common currency; France uses degrees French (°f), Germany degrees German (°dH). 1 °f = 10 mg/L.

    Bandmg/L°f°dHWhat it does to hair
    SoftUnder 60Under 6Under 3.4Lathers easily, rinses clean. Can leave fine hair limp and flyaway; conditioners feel heavier.
    Moderate60–1196–11.93.4–6.7The comfortable middle. Most routines work unchanged; a clarifying wash now and then keeps shine.
    Hard120–18012–186.7–10Minerals start to coat the strand: dullness, tangling, colour fade. Chelating washes enter the routine.
    Very hardOver 180Over 18Over 10Build-up is fast, especially on porous or bleached hair. Weekly chelation, richer conditioning, and a shower filter is worth it on long stays.

    Altitude, UV and your hair

    Height changes the sunlight and the air, not the strand itself. Both are in every city plan, alongside the water.

    UV climbs about 10–12% per 1,000 m

    Thinner air filters less ultraviolet, so the sun gets stronger with every kilometre up. UV breaks down keratin and lifts the cuticle: hair goes drier, rougher and weaker, and colour fades faster. At Tignes (2,100 m) the UV load is roughly a quarter higher than at sea level.

    Snow bounces it back up

    Fresh snow reflects most UV back at you, so an alpine resort in winter delivers it from above and below at once. That is why a ski week wrecks hair in a way a beach week at the same water hardness does not: UV damage, dry air and minerals landing together.

    Mountain air is dry air

    High air holds very little moisture, and cold air holds less again. Hair loses water to the air around it: dryness, static and flyaway ends, plus a dry, flaky scalp. Heated indoor air dries it further overnight. The fix is moisture and sealing, not more washing.

    Altitude bandElevationWhat changes for hair
    LowUnder 500 mSea-level rules: UV and air moisture are background factors, water hardness does the talking.
    Moderate500–1,500 mUV is measurably stronger and the air drier. Add a leave-in with a UV filter in summer and step up moisture a notch.
    HighOver 1,500 mUV protection becomes part of the routine, not an extra: colour fades faster, scalps burn along the parting, and dry air plus indoor heating pulls moisture out day and night.

    Elevations are approximate, from Open-Meteo elevation data at each city's map position. Treat them as planning guides, like the water figures.

    The Journal

    Notes on water, hair and travel. What the numbers on the map mean in the shower, in a hotel, and in your wash bag.

    ← Back to the Journal

    The water is different here

    Your shampoo did not change when you landed. Your water did. What hard water actually does to hair, why a week in a hotel exposes it, and what to do about it.

    By Good Hair Everywhere Journal 5 min read

    Every wash is two products, not one. There is the shampoo you packed, and there is the local water, which is an ingredient too, whether you chose it or not. Water hardness is simply how much calcium and magnesium the water picked up on its way through rock and soil, measured in milligrams per litre. Toyama in Japan runs at about 40. London runs at 320. Paris is 269. Cancún is close to 700. Same shower, same shampoo, completely different chemistry, and your hair can tell the difference within three or four washes.

    What the minerals actually do

    Hard water does not damage hair the way bleach or heat does. It coats it. Each wash leaves a thin film of mineral residue on the hair shaft, and the film builds. Hair that is coated feels rough and dry at the ends even when it is well conditioned, because the conditioner is now sitting on top of minerals instead of hair. Shine goes first, then softness. Colour follows: mineral build up dulls salon colour and makes it fade unevenly, and where the water also carries copper or iron, fair hair can pick up a greenish or brassy cast that no toner at home quite explains.

    There is a second, quieter effect. Hard water makes shampoo work harder for less result. The minerals react with cleansers, so you get less lather and more residue, and the natural response, washing more often with more product, adds more build up. People come home from a hard water city convinced a product has stopped working for them. The product is innocent. The water changed.

    The soft water problem nobody mentions

    Soft water is not automatically kind. In very soft water cities, Tokyo, Hong Kong and Vancouver among them, cleansers rinse almost too well. Shampoo strips efficiently, hair can feel squeaky and flyaway, and fine hair goes limp because there is no mineral weight in it at all. Travellers from hard water homes often over-wash in soft water cities and then over-condition to compensate. The fix is the opposite of the hard water fix: a gentler shampoo, less of it, and a light conditioner kept away from the roots.

    Why travel exposes it

    At home your hair and your water have reached an accommodation. Your routine, your products and your wash frequency are all tuned, without you thinking about it, to one water supply. Travel breaks the tuning in both directions at once. Hotel stays usually mean daily washing, hotter showers and unfamiliar products, so a week in London can lay down more mineral build up than a month at home. Then you fly somewhere soft and the same hair suddenly feels over-cleansed and thin. It is the contrast that makes it visible. Most people have had both problems on the same trip and blamed the hotel shampoo for both.

    What actually works

    The honest answer starts with a distinction the beauty industry blurs on purpose. A clarifying shampoo is a strong cleanser: it removes product build up, oils and silicones. A chelating shampoo does something different. It contains ingredients such as EDTA or phytic acid that bind to metal and mineral ions and carry them off the hair. Only the second one addresses hard water. A clarifying wash in a hard water city can leave hair feeling cleaner for a day while the mineral film stays exactly where it was.

    Used well, chelating is a small, occasional intervention, not a routine. In a hard water city, one chelating wash partway through a week, and a second near the end if the stay is long, is enough for most hair. Colour treated hair needs less: chelating also lifts colour, so the frequency drops and the rich conditioner matters more. In a soft water city, skip it entirely. There is nothing to remove.

    Shower filters sit in an awkward middle. A good one reduces chlorine, which is a real benefit for hair and skin, but it barely touches hardness, because dissolved calcium and magnesium pass straight through a carbon filter. If a filter promises to soften your hotel shower water, it is promising chemistry it cannot do. The only true fixes for hardness are ion exchange softeners and reverse osmosis, and neither fits in a suitcase. What fits is a plan: know the water where you are going, pack the two or three products that match it, and leave the rest of the shelf at home.

    A traveller's rule of thumb

    Under 60 mg/L, the water is soft. Go gentle, wash as normal, keep conditioner light. Between 60 and 120, you are in moderate territory: most hair copes, with one stronger wash in a week long stay. Above 120, treat it as hard water country: plan a chelating wash, take the richer conditioner, and if your hair is coloured, protect it like you would from the sun. Above 250, which includes London, Paris, Rome and much of the Mediterranean, the water is a real factor in how your hair will behave, and it is worth planning for rather than discovering on day four.

    That planning is what this site is for. The water map and the trip planner turn a city's number into a short list of what to bring. Your hair does not need more products. It needs the right ones, for the water you are actually standing under.

    ← Back to the Journal

    Hair at altitude

    The higher you go, the less air there is between you and the sun, and the less moisture the air holds for your hair. What altitude does to hair, and what a week in the mountains asks of your routine.

    By Good Hair Everywhere Journal 5 min read

    A mountain trip changes three things at once. The sunlight gets stronger, the air gets drier, and the water, which most people assume is soft because it comes from snow and springs, is often nothing of the kind. Hair that behaved all winter at home can come back from a ski week dry, faded and full of static, and its owner blames the cold. The cold is the least of it.

    The sun you cannot feel

    Ultraviolet light rises by about 11 per cent for every 1,000 metres of altitude. Thinner air filters less of it, so the same midday sun that is unremarkable at sea level does measurably more work at resort height. Tignes sits at 2,098 metres, where the UV load is roughly a quarter higher than on the coast, and it arrives in winter, when nobody is thinking about sun protection for their hair.

    What UV does to hair is slow chemistry. It breaks down keratin, the protein the strand is built from, and it lifts and roughens the cuticle, the overlapping outer layer that keeps hair smooth and shiny. The visible results are dryness, roughness and colour that fades weeks earlier than it should. Colour-treated hair shows it first. The scalp is skin, too, and it burns along the parting in a way people rarely connect to a day on snow.

    Snow sends it back up

    Fresh snow reflects most of the UV that hits it straight back up. On a glacier or a bright piste, your hair and scalp are lit from above and below at once, and the exposure runs all day, not just at noon. It is why a ski week is harder on hair than a beach week at the same water hardness: the beach has the sun, but the mountain has the sun twice, plus dry air, plus whatever minerals the local water carries.

    The air is dry, and the heating makes it drier

    Cold air holds very little moisture, and high air holds less again. Hair gives up its water to the dry air around it, between washes as much as during them. The results are the familiar mountain set: ends that feel like straw by day three, flyaway strands, and static that makes a brush crackle. Hats and helmet liners add friction on top: wool and fleece rub the cuticle the wrong way all day, which roughens the surface and builds the charge that lifts fine strands. Then you go indoors, where heated air is drier still, and the hair loses more moisture overnight. None of this is fixed by washing more. Washing is not where the water is going.

    The water is not always soft up there

    It is tempting to assume mountain water is soft: it fell as snow, after all. What matters is the rock it travelled through afterwards. Tignes runs at 150 mg/L, which is hard water, from the French health ministry's own network figures. Aspen, at 2,404 metres, runs at 215 mg/L, well into very hard territory. Denver is the counterexample that proves the rule needs checking: 1,598 metres up, with moderate water at 97 mg/L. Altitude tells you about the air. It tells you nothing reliable about the tap, which is why the planner holds the two as separate layers for every city.

    What to do differently

    Four changes cover most of it. First, treat UV protection as a daily product at altitude, the way you would sunscreen: a leave-in with a UV filter every morning, not just on beach days, and a hat or hood whenever you are out for hours. Lining matters: silk or satin under a hat cuts the friction that roughens the cuticle and feeds static.

    Second, step the conditioner up a weight, even where the water is only moderate. In Denver the water is not drying your hair; the air is, and a richer conditioner is the compensation. Third, set a mask rhythm: a deep conditioning mask mid week and another at the end of a ski week, because moisture loss at altitude is cumulative and a single treatment on the last night arrives after most of it has happened.

    Fourth, keep whatever hardness routine the water asks for. In Tignes the chelating wash still belongs in the week, on the plan's schedule, because mineral film and UV damage together are worse than either alone. And on the brightest days, covering your hair does more than any product applied afterwards.

    The planner on this site carries an elevation for every one of its 302 cities, and the plan adjusts for it: at high altitude it adds the leave-in with a UV filter, steps up the moisture, and in snow season adds a hat or helmet liner to the packing list. Put your resort in, and the altitude is already in the plan.

    ← Back to the Journal

    Hair in the tropics

    Humidity is a hair product you did not choose, applied all day whether you want it or not. What saturated air does to hair, why the water is rarely the problem, and the lighter kit that works in the tropics.

    By Good Hair Everywhere Journal 5 min read

    Step out of the airport in Bangkok and the air does something to your hair within the hour. It is not damage, exactly. It is physics, applied continuously, and most routines built for a temperate climate lose to it by the second day.

    Humidity, in plain words

    Hair absorbs water from the air. The strand is built from keratin proteins held in shape by weak hydrogen bonds, and water loosens those bonds temporarily, which is why wet hair can be restyled and why a style set in a dry room quietly comes undone in wet air. In saturated tropical air the process never stops. The cuticle, the strand's outer layer, swells as it takes in moisture, and it swells unevenly, so the surface roughens and neighbouring strands stop lying together. That is frizz: not dryness and not damage, but a strand full of air water, bending in its own direction.

    Curls, which are already bends, expand along them and grow outward. Straight hair tends to go limp at the root and rough at the ends at the same time, which is why tropical frizz confuses people: the top is flat and the bottom is a cloud. No product changes the weather. The aim in the tropics is not to defeat humidity but to slow it down and keep the strand's own moisture where it belongs.

    Sweat, scalp and the washing question

    Heat means sweat, and sweat plus the scalp's own oil makes a scalp feel unwashed faster than the hair below it actually is. The answer is to wash more often, and in the tropics that is correct, provided the washing is gentle. Use a mild shampoo, a small amount, and aim it at the scalp, which is where the sweat and oil are. Let the rinse carry it through the lengths. A strong shampoo used daily to chase the feeling of freshness will strip the strand, and stripped hair in humid air frizzes harder, because a raised cuticle takes in air moisture even faster. A rinse with water alone, or with conditioner only, covers the in-between days for most hair.

    The water is mostly moderate

    Here is the good news the map shows: most tropical cities sit in the moderate band, where most routines work nearly unchanged. Bangkok runs at 90 mg/L, an official figure from the Metropolitan Waterworks Authority. Kuala Lumpur runs at 65 mg/L. At those numbers there is no mineral film to chelate away, and one stronger wash in a week is a reset, not a necessity. The exceptions are the limestone coasts: Cancún, where the aquifer runs through limestone, is close to 700 mg/L, some of the hardest water in the dataset. Tropical does not guarantee moderate, which is why the number is worth checking rather than the climate assumed.

    The second climate is indoors

    Tropical days are a swing, not a steady state. Saturated street air, then an air conditioned room cold and dry enough to feel like another country, then back out again, several times a day. Each swing swells and then dries the strand, and hair that swells and shrinks repeatedly through a holiday comes home tired: rougher, duller, more prone to tangle. You cannot opt out of the swing, but a leave-in conditioner worn through the day blunts it, holding moisture in the strand and smoothing the cuticle the street air is trying to lift.

    Sea, pool, and the rinse first rule

    Salt water dries hair and leaves it rough and tangled; pool chlorine strips it and can leave fair hair with a greenish cast. The single most useful habit costs nothing: rinse your hair with clean water before you swim. A dry strand takes up water like a sponge. A strand already full of clean tap water takes up far less of the sea or the pool. Rinse again when you come out, and wash properly at the end of a swimming day, gently. The damage people bring home from a beach holiday is usually a week's un-rinsed salt and chlorine, not the swimming itself.

    The tropical kit

    It is a short list, and it is lighter than the temperate one. An anti humidity leave-in is the core product, worn daily: it is the layer that slows the air's water getting in. Conditioner goes down a weight, not up: heavy masks in humid air weigh hair down and seem to melt out of it by midday, so a light or mid-weight conditioner, ends only, does more. The gentle shampoo earns its place because of the washing frequency, and the richer products stay home.

    In the planner, this is already wired in. Cities carry their humid months in the dataset, and Bangkok's run from May to October. A trip in those months puts the anti humidity serum and the leave-in with a UV spray on the packing list without being asked, next to the moderate water's simple washing plan. Check your destination's number and its season before you pack. In the tropics the water will probably be kind. It is the air you are dressing for.