Why Summer Sunlight Is Your Secret Energy Weapon (And How to Use It Wisely)

Longer days, lighter evenings, and (if we’re lucky) the warmth of the sun on our skin — there’s something unmistakably uplifting about summer. That extra boost in mood, sleep quality, and motivation isn’t just coincidence — it’s biology. Summer sunlight and energy are deeply connected, and the way we engage with light during these brighter months can have a profound effect on our hormones, mood, and daily rhythm.

Our bodies evolved to run on natural light. But modern life — full of screens, indoor offices, and unpredictable routines — often cuts us off from the very thing that fuels us.

In this post, I’m unpacking how summer sunlight can be your not-so-secret weapon for more energy, balanced hormones, and better mood — without needing to overdo it or fear the sun.

The Power of Morning Light

If you do one thing this summer to boost your energy and feel more like yourself, make it this: get outside in the morning.

Morning sunlight is like a reset button for your circadian rhythm — your internal body clock. That rhythm influences everything from your cortisol awakening response (which gives you morning energy) to your melatonin release at night (a key sleep hormone).

When natural light hits your eyes in the morning, it tells your brain, “It’s daytime now — let’s go!” Your body responds by:

• Lowering melatonin production so you feel more awake
• Increasing cortisol (in a healthy, energising way)
• Setting a timer for melatonin to kick in roughly 14–16 hours later (as long as there is no artificial light after sunset) — making it easier to wind down at night

It also helps regulate your hunger hormones, blood sugar rhythms, and body temperature — all of which play a huge role in how energised (or flat) you feel through the day.

Even 10–15 minutes outside shortly after waking (preferably within an hour of sunrise) can make a big difference. Ideally, aim for light on your skin and through your eyes without sunglasses (we’ll come to that later). Walk, sit with your cuppa, or potter in the garden — whatever feels doable.

UV Light, Vitamin D, and Mood

While morning light is mostly about brightness (lux) and circadian rhythms, UV exposure — particularly in the late morning to early afternoon — is key for vitamin D production.

Vitamin D isn’t just a bone health thing. It’s vital for immune function, mood regulation, inflammation, and hormonal balance. Low levels are linked with fatigue, brain fog, PMS, and even low motivation or mood dips.

In the summer months, especially in the UK and Ireland, the sun is finally strong enough for your skin to make vitamin D — but only if it’s exposed.

That doesn’t mean baking in the midday sun. A short burst of exposure (e.g., arms and legs uncovered for 10–30 minutes depending on skin tone) a few times a week can often be enough to top up your levels – and this form of vitamin D can be stored in the body for slow release throughout the winter months!

One Size Doesn’t Fit All: Skin Tone and Vitamin D

When it comes to vitamin D, it’s also important to recognise that our needs vary.

Melanin — the pigment that gives skin its colour — naturally blocks UVB rays, the very rays your skin needs to convert cholesterol into vitamin D. That means the more melanin you have (i.e., the darker your skin), the longer you generally need to spend in the sun to produce enough vitamin D.

If you have very fair skin, you might only need 5–15 minutes of mid-morning sun on your arms and legs to meet your needs. If your skin is naturally deeper in tone, you might need 30 minutes or more, depending on your location and the time of year.

This is why a ‘one-size-fits-all’ sun advice approach doesn’t really work. It’s also one reason many people — especially those with darker skin tones living in northern climates — are more likely to be deficient in vitamin D, even in summer.

Staying Cool and Safe Without Missing Out

Of course, we’ve also been taught to fear the sun — and yes, too much unprotected exposure can cause skin damage. But that doesn’t mean we should avoid it altogether. There’s a sweet spot between “sun-fearing” and “sun-worshipping.”

A few tips:

• If your skin is very sensitive to the sun, get your sun time earlier in the day or later in the afternoon, when UV isn’t at its peak
• Use clothing, shade, or mineral-based sunscreen to protect if you’ll be out longer
• Avoid burning — ever
• Listen to your skin and your body

The aim is sensible, intentional exposure — not endless tanning or total avoidance.

A Quick Word on Sunglasses and Sunburn

Now, this might surprise you: wearing sunglasses all the time in bright daylight can increase your risk of sunburn. Here’s why.

Our eyes aren’t just for seeing — they’re also key players in how our bodies respond to sunlight. When your eyes are exposed to bright natural light, they send signals to your brain that help regulate all sorts of internal processes, including melanin production — the pigment that offers some protection against UV damage.

Wearing dark sunglasses for long periods during strong sunlight can reduce this signalling, tricking your body into thinking it’s not sunny at all. That means your skin might not gear up its defences as it should, making you more prone to burning.

This doesn’t mean you should never wear sunglasses — but it’s worth thinking about when and why you reach for them. If you’re just popping out for a short walk in the morning or standing in dappled shade, allowing your eyes to soak in that light can be a subtle but powerful way to support your natural sun-protection rhythms.

What If You’re Indoors All Day?

Not everyone has the luxury of a morning walk or lunchtime lounge in the garden — especially if you’re juggling work, kids, and a never-ending list of errands. But there are still things you can do:

• Open windows to let natural light in
• Work near a window whenever possible (with the window open – glass distorts light wavelengths)
• Take short breaks outside — even 5 minutes can help
• Swap your screens for a quick sit in the garden or on the doorstep when you can

If you’re waking up groggy, struggling to sleep, or feeling “wired but tired,” lack of natural light might be playing a bigger role than you think.

Reconnect with Nature’s Rhythm

Using summer sunlight to your advantage isn’t about doing more or adding stress to your day. It’s about gently syncing back up with nature’s rhythm — a rhythm your body still remembers, even if modern life has nudged it out of tune.

Start small:

• Step outside for your morning coffee
• Open your windows and let the light in while you eat breakfast or go about your morning
• Open the back door (or a window) while you’re folding laundry

Your body is paying attention — and often, these tiny tweaks can spark a surprisingly big shift in how you feel.

If you’re curious about how to reconnect with your body’s natural rhythm for better energy, better sleep, and more calm in the chaos, that’s exactly what I help my clients do.

📩 You can sign up for my newsletter HERE, catch up on previous blog posts HERE or book a free wellness check-in call HERE if you’d like more personalised support with creating realistic rhythms or nutrition plans that work for your life.

A gentle reminder: This post is for educational purposes only and isn’t intended as medical advice. Please speak to a qualified health practitioner if you have specific concerns about sun exposure, vitamin D, or your personal health.