✨ How to protect your hair in summer from sun, salt and chlorine

Summer is the most beautiful season, but also the hardest on hair. Sun, salt and chlorine work together to dry out the fibre, dull the shine and alter the colour, leaving the lengths matte and brittle just when we would most like to show them off. The good news is that a few targeted gestures, and the right products, are enough to come back from holiday with healthy, luminous hair.

At Alexim Atelier Duomo, in Via Mazzini 16 in Milan, we prepare our clients for the season with a bespoke protection strategy. In this guide we explain why sun, sea and pool put hair to the test, and above all how to defend it day by day, with special attention for anyone who has coloured or lightened hair.

💎 Why sun, salt and chlorine put hair to the test

The three enemies of summer act in different ways but with a similar result: drier, more fragile hair, often in a less vibrant colour. UV rays weaken the keratin and oxidise the pigments, fading the colour and making the fibre porous. Salt has an osmotic effect, drawing water out from inside the hair and leaving the cuticle rough. Chlorine, finally, is the most aggressive: it dissolves the natural protective film and can turn blondes towards unwanted tones.

Understanding these mechanisms is the first step to defending against them. It is not about giving up the sea or the pool, but about supporting the hair with the right care before, during and after exposure.

✨ Protecting hair from the sun

Just like the skin, hair too needs a sun filter. There are sprays and oils with specific UV protection, to apply to the lengths before exposure and to reapply after every swim. They are light, do not feel greasy and make a real difference in preserving colour and softness.

During the middle of the day, when the sun is strongest, a wide-brimmed hat remains the most elegant and effective protection. And it is best to avoid exposing wet hair for long: the damp fibre is more vulnerable and absorbs both UV rays and salt more easily.

💎 Hair and the sea: defending against salt

The most effective trick is simple: wet your hair with fresh water before going into the sea. A fibre already saturated with water absorbs far less salt, just like a sponge that is already wet. Applying an oil or a leave-in first also creates a barrier that limits the assault of the salt.

After swimming, always rinse your hair with fresh water as soon as possible, to remove the salt before it dries and crystallises on the fibre. In the evening, a hydrating mask gives the lengths back the water lost during the day.

✨ Hair and the pool: watch out for chlorine

The same principle as the sea applies: wetting your hair with fresh water before diving in reduces the absorption of chlorine. Straight afterwards, a thorough rinse is essential, because it is the chlorine left on the fibre that does the most damage, especially on lightened hair, where it can create that annoying greenish tint.

If you swim often, an occasional gentle clarifying shampoo helps remove the accumulated residue, but without overdoing it so as not to dry the hair further. On blondes, a professional treatment on your return is often the best solution to bring the colour back to its full brilliance.

💎 The summer routine, day by day

Putting these measures together into a simple routine is the best way not to forget them. Here are the essential gestures for every sunny day.

• 💎 In the morning: apply a leave-in or an oil with a UV filter to the lengths.
• ✨ Before swimming: wet your hair with fresh water to saturate it.
• 💎 After swimming: rinse immediately with fresh water to remove salt or chlorine.
• ✨ At peak hours: protect with a wide-brimmed hat.
• 💎 In the evening: gentle shampoo and a hydrating mask to replenish water and nourishment.

You will find our selection of professional sun products, designed precisely for the fibre exposed to the sun, in the guide to the Soleil Kérastase line.

💎 The Soleil Kérastase line: professional sun care for hair

When it comes to professional sun protection for hair, the reference is the Soleil Kérastase line, one of the most solid and recognised sun ranges in the professional market. Its formula combines UV filters, Babassu oil, vitamin E and coconut water: the filters screen the rays and prevent the colour from fading, while the other active ingredients nourish the fibre and maintain its hydration even after hours in the sun.

The range is made up of three products that cover the entire summer routine: the Bain Après-Soleil, the after-sun shampoo that removes salt and chlorine without attacking the colour; the Huile Sirène, the iconic bi-phase spray oil with UV filters that protects, tames and creates a luminous beach-waves effect; and the Masque Après-Soleil, the mask for intensive repair. If you had to choose just one, the Huile Sirène is the product to pack in your suitcase.

At Alexim Atelier Duomo you will find the Soleil line for retail, even without booking a treatment: a short consultation is all it takes to choose the right products for your holiday. You will find all the details, the sizes and the complete routine in our dedicated feature on the Soleil Kérastase line.

✨ Coloured and lightened hair: extra care

Anyone with coloured hair, and even more so anyone who has lightened it, needs to double the care. The sun tends to shift the reflections and fade the colour, while salt and chlorine accentuate the effect. Constant UV protection and the use of sulphate-free products help keep the shade clean for longer.

If you have chosen a summer 2026 balayage or an Airtouch with a sun-kissed effect for the summer, protecting them well means keeping them luminous until September. A periodic toner, done in the salon, keeps the reflection fresh and neutralises any unwanted tones.

💎 The role of professional treatments

Home care is fundamental, but some interventions are at their best in the salon. Before you leave, a rebuilding treatment strengthens the fibre and prepares it for the stress of the warm months; on your return, the same treatment repairs the accumulated damage and restores elasticity and shine.

For more stressed hair we often work with the Résistance Kérastase line, while a bespoke in-salon treatment lets us respond to the needs of your hair in a tailored way. During the consultation we assess the most suitable path, before and after the summer.

✨ Frequently asked questions about protecting hair in summer

How do I protect my hair at the beach?
Apply an oil or a leave-in with a UV filter before exposure, wet your hair with fresh water before going into the sea, and rinse it straight after swimming to remove the salt.

Does chlorine turn blonde hair green?
It can happen, especially on lightened hair, because of the residue that settles on the fibre. Rinsing immediately with fresh water and a professional treatment on your return solve the problem.

Do I have to wash my hair every day on holiday?
It is better to avoid washes that are too aggressive and frequent. A fresh-water rinse after swimming is essential, while a gentle shampoo in the evening, followed by a mask, is enough to keep the hair clean and hydrated.

Which sun product should I choose for my hair?
Look for sprays or oils with specific UV protection for hair, light and easy to reapply. In the salon we recommend the product best suited to your fibre and your colour.

Does the sun fade colour?
Yes, UV rays oxidise the pigments and fade the shade, especially on coloured and lightened hair. Constant protection and sulphate-free products help keep the colour for longer.

Can I have a treatment before my holiday?
It is highly recommended. A rebuilding treatment strengthens the fibre and prepares it for the stress of sun, salt and chlorine, reducing the damage of the season.

What should I do when I get back from holiday?
A professional rebuilding treatment and, for anyone with coloured hair, a toner to revive the reflection. Often a single session is enough to bring the hair back to its full brilliance.

Does salt ruin the style?
Salt dries the fibre and creates a rough effect, but with oil and a hydrating mask softness and movement are easily recovered.

Can I use oil on my hair in the sun?
Yes, but choose an oil formulated with a UV filter designed for exposure. Generic oils without protection can accentuate the effect of the heat on the fibre.

Should I trim the ends after summer?
A trim on your return often removes the most stressed ends and makes the hair look healthier straight away. We assess it together based on the condition of the fibre.

Are curly and straight hair protected in the same way?
The principles are the same, but curly hair tends to be drier and welcomes more intense hydration. During the consultation we personalise the routine based on your texture.