Summer has a way of changing our skin, often in ways we don't expect.

One week your complexion feels comfortable. The next it seems a little oilier, tighter after cleansing or more prone to the occasional breakout. Even skin that feels settled throughout winter can become less predictable as the weather warms up.

It's tempting to think your skin suddenly needs an entirely new routine. More often, it simply needs a few thoughtful adjustments. Understanding why your skin behaves differently in summer makes it much easier to care for it with confidence.

Why does skin change during summer?

Warmer weather changes how your skin behaves. Heat, UV exposure, humidity, air conditioning and more time outdoors can all influence how well your skin retains moisture, how much oil it produces and how comfortable it feels throughout the day.

Rather than overhauling your skincare routine, small seasonal adjustments are often enough to help keep skin balanced.

What you'll discover

• Why does summer affect your skin differently?
• Why can skin feel oily and dehydrated at the same time?
• Why is SPF even more important during summer?
• Can hot weather trigger breakouts?
• Can nutrition support healthy summer skin?
• How can you help your skin recover after a day in the sun?
• Summer Skin Takeaways
• FAQs

Why does summer affect your skin differently?

Your skin is constantly adapting to its surroundings, and summer simply asks a little more of it.

Longer days outdoors, rising temperatures and changing humidity place extra demands on the skin barrier, the protective outer layer that helps keep moisture in while defending against everyday environmental stressors.

Unlike winter, where dryness is usually easy to recognise, summer can be more misleading. Skin may appear shinier while quietly becoming dehydrated beneath the surface. It's one reason your complexion can feel very different by the evening than it did over breakfast.

Understanding these changes makes it easier to respond with care rather than correction.

The Science of Summer Skin

Every skin responds differently to summer, but these seasonal changes help explain why products that felt perfect a few months ago may suddenly feel less effective.

Heat encourages water loss

Warm weather naturally increases perspiration as your body regulates its temperature. As water evaporates from the skin's surface, moisture is lost too. It's one reason skin can feel surprisingly tight after a hot day, even when it looks oily.

UV exposure creates invisible stress

Sunlight does more than warm the skin. It also generates free radicals that contribute to oxidative stress, placing additional pressure on the skin barrier. Over time, this can affect how comfortably your skin retains moisture and contribute to the visible signs of premature skin ageing.

Air conditioning changes your skin's environment

Moving between outdoor heat and cool indoor spaces exposes your skin to rapid changes in temperature and humidity. It's one reason skin can feel comfortable outside but noticeably tighter after spending several hours in an air-conditioned office, aeroplane or car.

Swimming can leave skin feeling drier 

Whether you're swimming in the sea or a chlorinated pool, both salt water and chlorine can temporarily leave skin feeling less comfortable. A gentle cleanse followed by lightweight hydration is often enough to help restore comfort.

Why can skin feel oily and dehydrated at the same time?

One of the biggest misconceptions about summer skincare is that oily skin can't be dehydrated.

In reality, oil and water do very different jobs. Sebum helps lubricate the skin, while hydration refers to the amount of water held within it. During warmer weather, your skin may produce more oil in response to heat while losing water more quickly through evaporation. Sweat helps cool the body, but it doesn't replace the water your skin has lost.

The result is skin that looks shinier than usual but still feels tight, uncomfortable or thirsty.

Rather than trying to strip away excess oil, focus on replenishing hydration while helping your skin retain it.

Reviver Hydrating Mist was created for moments like these. With prebiotic inulin, L-arginine and soothing aloe vera, it delivers lightweight hydration while helping to maintain a comfortable, healthy-looking complexion.

Its ultra-fine mist absorbs quickly without feeling sticky, making it easy to use after cleansing, over makeup or whenever your skin needs a refreshing lift.

Why is SPF even more important during summer?

Summer usually means more time outdoors, whether you're walking the dog, enjoying lunch in the garden or heading away for a few days. With that comes greater exposure to UV rays.

Daily sunscreen does more than help prevent sunburn. It also protects against the cumulative effects of UV exposure, which can contribute to dehydration, uneven skin tone and the visible signs of premature skin ageing.

Broad-spectrum SPF protects against both UVA and UVB rays. While UVB rays are best known for causing sunburn, UVA rays penetrate deeper into the skin and contribute to oxidative stress and long-term skin ageing.

Serene Daily SPF 50+ was developed specifically for sensitive skin. Dermatologically Approved for sensitive skin, it provides broad-spectrum UVA and UVB protection in a lightweight, moisturiser-like formula that feels comfortable to wear every day, with or without makeup.

Serene Daily SPF 50+ has also been featured by Caroline Hirons in her Caring for Your Skin During Cancer Treatment guide on the Skin Rocks app, where she highlights it as a suitable option for sensitive skin. The formula was inspired by By Sarah co-founder Lauren's treatment-sensitised skin and developed with comfort, simplicity and everyday wear in mind.

★★★★★

"Best SPF I have ever used. I use it all year round. It doesn't interfere with my make-up and feels like a treat for my sensitive skin."

— Kelly

Apply generously every morning as the final step of your skincare routine and reapply regularly, particularly after swimming, perspiring or towel drying. During prolonged sun exposure, combine SPF with shade, protective clothing, a hat and sunglasses.

Can hot weather trigger breakouts?

Hot weather can contribute to breakouts because perspiration, excess oil, sunscreen and pollution build up more quickly on the skin. Heat itself is rarely the only cause, and over-cleansing can leave sensitive skin feeling even more reactive.

Rather than reaching for harsher products, keep your routine simple and consistent.

At the end of the day, Balancer Cream Cleanser gently removes sunscreen, excess oil and daily impurities without leaving skin feeling stripped, helping your skin feel clean, comfortable and ready to recover overnight.

If blemishes do appear, Ally Recovery Blemish Facial Oil offers lightweight support for skin that feels congested or unsettled. Rather than drying out blemishes, it helps calm the appearance of breakouts while supporting your skin as it recovers.

Sometimes the most effective approach is also the gentlest. Giving your skin the space to recover often leads to better long-term results than trying to treat every blemish aggressively.

Can nutrition support healthy summer skin?

Your skin is influenced by more than the products you apply.

Summer often brings changes to our routines, from travel and warmer weather to different eating habits and disrupted sleep. These small shifts can all influence how your skin looks and feels.

Staying hydrated, enjoying plenty of colourful fruit and vegetables and including healthy fats as part of a balanced diet all contribute to healthy skin. Water-rich foods such as cucumber, melon, berries and citrus fruits are simple ways to support hydration during warmer weather.

Research into the connection between the gut and the skin continues to grow.

Flora Daily Biotic was developed with both gut and skin health in mind. It contains 20 billion live cultures from clinically studied strains, including Lactobacillus acidophilus LA85 and Bifidobacterium longum BL21, alongside 100% of your recommended daily intake of zinc, which contributes to the maintenance of normal skin and normal immune function.

Delayed-release capsules help the live cultures reach the gut, while the clean formulation contains no preservatives, sugars, sweeteners or colours. It's a simple addition to your daily routine, whether you're enjoying summer at home or travelling further afield.

How can you help your skin recover after a day in the sun?

A day in the sun asks a little more of your skin than you might realise. Heat, UV exposure, perspiration and even air conditioning can all leave it feeling less comfortable by the evening.

The aim isn't to undo the day. It's simply to help your skin recover comfortably overnight.

Begin by gently cleansing away sunscreen, perspiration and daily impurities with Balancer Cream Cleanser.

Follow with Reviver Hydrating Mist to replenish lightweight hydration before the rest of your evening routine.

If your skin looks a little dull the following morning, gently pat and press Vitamin C+E Facial Oil onto the face and neck as the final step in your morning skincare routine, before applying Serene Daily SPF 50+. Its slow-release vitamin C, paired with vitamin E, squalane, jojoba and grapeseed oil, provides antioxidant support while helping restore a brighter, healthier-looking complexion.

Recovery isn't only about skincare. Staying hydrated, enjoying nourishing foods and getting enough rest all help your skin recover naturally.

Summer Skin Takeaways

• Summer can leave skin feeling oily and dehydrated at the same time.
• Heat, UV exposure, air conditioning and swimming can all affect your skin barrier.
• Lightweight hydration and daily SPF help support healthy, resilient skin throughout the season.
• Gentle cleansing is often more effective than over-cleansing when skin feels congested.
• Looking after your skin from within, alongside a consistent skincare routine, helps support healthy skin all summer long.

FAQs

Why does my skin feel oily but tight during summer?

Heat can increase oil production while water evaporates more quickly from the skin. This means skin may appear shinier than usual while still lacking hydration beneath the surface.

Should I moisturise during summer?

Yes. Rather than skipping moisturiser altogether, choose lightweight, barrier-supportive formulas that help your skin retain moisture without feeling heavy.

Is Vitamin C good to use during summer?

Yes. Vitamin C is a powerful antioxidant that helps protect against free radicals generated by UV exposure and pollution while supporting brighter, more even-looking skin. Apply Vitamin C+E Facial Oil before your SPF as part of your morning routine.

Can SPF cause breakouts?

Some sunscreens may not suit every skin type, but a lightweight, non-comedogenic formula designed for sensitive skin is less likely to feel heavy or contribute to congestion. Cleansing thoroughly each evening also helps remove sunscreen and daily impurities.

Can probiotics help support healthy skin?

Emerging research continues to explore the relationship between the gut and the skin. Looking after your gut alongside a balanced diet and consistent skincare routine may help support overall skin wellbeing.

Explore more from the Journal

• How to Prevent Summer Breakouts: A Sensitive Skin Guide
• Aeroplane Skincare: How to Protect Your Skin When Flying
• The ultimate summer skincare routine

Your skin changes with the seasons. Your routine can too.

We know that caring for sensitive skin isn't always straightforward, and we're always happy to help. You're always welcome to email us at care@bysarahlondon.com or send us a message on @bysarahlondon. We also share seasonal skincare advice, nourishing recipes, gentle wellbeing tips and simple rituals to help you care for your skin from the inside out.

 

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