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Spring and summer are everyone’s favorite times to play outside. And for good reason. But just because the sun’s out and temps are rising doesn’t mean every inch of your delicate epidermis should be on display. On the contrary, the best way to protect yourself from damaging UVA and UVB rays, sunburn and early aging (without having to slather on sunscreen every hour) is to don a breathable sun shirt. A sustainable one, of course.
What is a sun shirt and why are they an excellent option in warm weather? For a number of reasons. First, they keep you covered and from suffering damaging effects of the sun. Many even have UPF ratings so you know they’ve been tested for adequate sun protection. Second, they can seriously slash your annual sunscreen budget in half. And third, despite being long-sleeved, they can actually help keep you cool by keeping the sun from beating down on bare skin and aiding in evaporation via sweat wicking. Get one with a hood and it can even protect your neck and face (when paired with a hat, of course). Bonus: they also double as base layers in cooler temps, especially if you opt for a sun shirt vs a sun hoodie.
But not all long sleeve sun shirts are designed with hot weather in mind. Fortunately, we found five comfortable, breathable sun shirts for women and men to keep you cool and happy on every type of adventure.
Just don’t forget the sustainable sunscreen for any skin not covered by fabric.
Looking for more options? Check out this post full of sustainable sun hoodies.
Actually Breathable Sun Shirts for Summer Hikes

Cotopaxi Sombra Sun Hoodie: The Best Combo of Breathability and Performance
This is one of my favorite breathable sun shirts for a few reasons: It’s light and loose, has a functional hood, and the fabric is textured and non-plasticky, meaning it never feels clingy even when working hard in hot weather. It feels breezier, which is a welcome feature in a sun shirt designed for warm weather.
This sun shirt for men and women also has thumb holes, a roomy hood that offered the perfect amount of semi-fitted protection that always stayed put, and a small zippered pocket on the back, which is a good place to store lip balm or a gel packet on hikes or trail runs.
It’s lightweight, offers UPF 50+ protection, and is treated with Polegeine anti-order tech so it doesn’t stink quite as much (or as quickly) so you won’t have to wash it after every use. It also feels more durable than some other lightweight sun shirt options and like it will last for plenty of seasons of outdoor fun.
How it’s sustainable: Made of 100% recycled polyester. Cotopaxi is also committed to ethical and sustainable manufacturing and transparent about their progress.
Sizes Available: Women: XS-XL, Men: S-XXL

Freefly Bamboo Lightweight Long Sleeve: Softest Sun Shirt for Day Hikes
If you’re looking for something that features more natural fibers, but aren’t interested in wool (because you’re vegan like we are or whatever other reason), take a peek at the Freefly Bamboo shirt. This is by far the most breathable and comfortable shirt we tested, but also not the most technical. Meaning it won’t perform as well for sweaty, high-output pursuits simply because it won’t wick moisture as well or dry as quickly. But for day hikes, afternoon mountain bike excursions, and afternoons in the park, it’ll do just fine (and look less like you’re planning to summit a mountain later).
It’s soft to the touch, super duper lightweight, feels nice on skin, and is plenty breathable, making it great for warm, sunny days. It’s not super fitted, but we like that about it, honestly. And the cut is such that it still doesn’t look frumpy. It does only offer UPF 20+ protection, but since it’s still covering your skin, it’s still performing better than a T-shirt.
It’s made of 70% viscose from bamboo and 30% Polyester, so it still retains some moisture-wicking properties while being naturally odor resistant. Basically, this is a shirt for when you don’t need all the over-built performance qualities of more extreme (and expensive) outdoor clothing. It’s also available in a hooded version. I wore this shirt on a warm day of mountain biking recently and loved that I didn’t feel like I had to peel it off immediately after returning to the parking lot. It was comfy, soft, and available in plenty of colors. I’d happily don this shirt for less extreme pursuits.
How it’s sustainable: The bamboo Free Fly uses is organic and FSC certified and they’re suppliers and manufacturers must adhere to the brand’s restricted substances list and code of conduct.
Sizes Available: Women: XS-XXL, Men: S-XXXL

Patagonia Capilene Cool Trail Shirt: Best for that Natural Fiber Feel
Sometimes you just don’t want the feeling of sweaty polyester on your skin. When that’s the case, turn to the Patagonia Capilene Cool Trail Shirt, which is still partially made out of recycled polyester (and fabric made of wood pulp), but manages to feel more like a natural fiber. How do they do it? We don’t know. Magic maybe? Science? Either way, it feels nice on the skin, breathes like cotton, and still dries fast. Not as fast as a lightweight synthetic, perhaps, but especially for hot day hikes and other warm-weather activities, we don’t mind at all (in hot, dry climates, plant-based fibers are more than welcome).
There are only a few colors available, and it’s not the most size-inclusive option on the list, but we can forgive that since this crew neck sun shirt is not only comfy, but looks good enough to wear in day-to-day life, too. And since it doesn’t have a hood, it works just as well for mountain biking and as a base layer in cooler weather as it does for hiking. It’s semi-fitted without being too baggy or too snug, making it quite the goldilocks option for outdoor adventure.
It’s not UPF rated, and there are no thumb holes, but we’ve never complained during long days on the trail.
How it’s sustainable: Made of recycled polyester and renewable wood pulp fiber, Fair Trade certified.
Sizes Available: Women’s: XS-XXL, Men’s: XS-XXXL

Helly Hansen Shine Solen: Best Light and Loose Sun Shirt
Thin, light, and loose, this breathable sun shirt is perfect for warm weather hiking and just about any other outdoor activities. It packs down super small, weighs little, and is available as a men’s sun shirt with a hood and a women’s sun shirt without. The men’s/unisex hooded version even has a small zipper pocket on the chest.
It does only come in a few colors, but if you tend to lead toward neutrals instead of bright colors, then this might be the shirt for you. It’s also UPF 50+ rated, which is impressive for such a lightweight shirt. It also wicks sweat and dries like a boss and is impressively stretchy. There are no thumb holes, but we don’t think that’s a dealbreaker.
The material can feel clingy when damp because it’s smooth, not textured, but it’s micro perforated, so stupendously breathable. It also fits on the loose side (I’m pictured wearing an XS) and the women’s cut is more boxy than curvy, which all makes the shirt feel less sticky and clingy and more comfortable in hot weather.
How it’s sustainable: Made with 80% recycled polyester plus elastane for stretch and is a Bluesign product.
Sizes Available: Women: XS-XL, Men: S-2XL

Outdoor Research Echo Hoodie: Best Ultralight Sun Hoodie
On warm hikes, this is the shirt I often turn to first. It’s ultralight, packs down ultra small, is breathable and thin and still protects my skin from harsh sun. Plus it’s available in a wide array of color and patterns that pop on camera. This summer sun shirt is slightly less protective than other options on this list (UPF 15), but for most people, that’s sufficient. I’ve never been sunburned once while wearing this shirt, including on sunny multi-day hikes.
It’s more fitted than other options, so if you like your sun shirts loose, size up. If not, or if you’re small like I am, you’ll be happy to know this is an option that’ll fit. Bonus: it comes in plus sizes, too, up to 4XL. There are thumbholes to help protect your hands and the women’s version even has a port in the back of the hood for a ponytail or braid. There’s also a non-hooded version if you prefer a crew neck sun shirt.
As for the material, it’s perforated to offer maximum airflow and super thin and light. That means it’s breathable, but maybe less durable than some of these other options. That said, over several seasons of wear, I’ve only managed to inflict one snag, so I’m OK with that. The fabric can feel a bit clingy when damp since it’s not textured, but given all the other benefits, it’s still a winner in my book.
How it’s sustainable: Made of Bluesign approved 100% recycled polyester.
Sizes Available: Women’s: XXS-4XL, Men’s: S-3XL
Bottom Line
Choosing the right sustainable, breathable sun shirt is a personal decision and everyone is looking for. little something different. So choose one that’s right for you and that you’ll want to wear for many seasons to come. And if you have any questions about them, ask away in the comments below. We’re always happy to help fellow outdoorists buy once and buy right so less goes to waste. Remember, too: buying used on sites like Geartrade and REI Re/Supply is always an excellent, sustainable, money-saving option. So protect that epidermis and wander on!
Alisha is a freelance outdoor journalist and photographer based in Ogden, UT. She loves backpacking, hiking, mountain biking, kayaking and snowboarding (even though she’s terrible at it). She’s also pretty sure she’s addicted to coffee. alishamcdarris.com