Whether you’re grinding up a sweaty climb, moving through wind-blown ridgelines, or hiking through pouring rain, the UL All-weather Hoody is built to stay on—not packed away. Light, breathable, and weather-ready, it’s made for moving through changing conditions without stopping to change layers.

At the core of the system is Pertex Shield Air, a waterproof-breathable fabric with exceptional airflow that redefined what rainwear could feel like in motion. But that breathability came with a tradeoff: as the DWR wore down, so did its water resistance.

For the 2026 version, we rebuilt the jacket with a mapped construction that combines two Pertex fabrics. Shield Pro is placed in high-exposure areas for added weather protection, while Shield Air remains under the arms and across the back where ventilation matters most. The result is greater confidence in heavy rain without losing the signature breathability that defines the UL All-weather series.

Among the series, the UL All-weather Hoody is the most minimal expression of the concept. With no zipper and fewer potential points of water entry, it delivers serious weather protection in a super-light 120g (Size S) package that feels soft, breathable, and barely there.

*For details on the 2026 specification update, see here.

Rainwear keeps rain out, but it also traps heat. The harder you move, the faster it gets clammy—so when the rain stops, you take it off.

Wind shells are light and breathable, but they are not built for real rain.

For years, hikers had to choose between the two: protection or breathability.

Nanofiber membranes changed that. By allowing air to pass through while keeping water out, they made it possible to create a shell that stays comfortable across changing conditions—not just when it rains.

This is not simply rainwear, and it is not simply a wind shell. It is a new category built for movement in all weather: all-weather activewear.

Pertex Shield Pro and Pertex Shield Air solve different problems.

Shield Pro balances waterproofing and breathability, making it the right choice for areas that take the full force of rain: the hood, front body, and outer arms.

Shield Air is built for true breathability — letting air pass through the fabric. We use it where heat and moisture build up most: across the back, under the arms, and along the inner arms.

By placing each fabric where it performs best, the UL All-weather Hoody gains more confidence in the rain without losing the airy feel that defines the series. Shield Pro takes the weather. Shield Air lets the body breathe. Together, they create a shell built to stay on through changing conditions.

The UL All-weather Hoody is not trying to be a conventional rain shell.

Compared to typical 200–300g waterproof-breathable hiking rainwear, it puts greater emphasis on lightness, air permeability, and comfort in motion. The tradeoff is lower heat retention and lower water resistance than heavier rainwear, so layering and conditions still matter.

At 120g (Size S), its strength is clear: real weather protection in a super-light shell built to stay on through changing weather.

Pertex Shield Air does more than release moisture. It lets air move through the fabric.

That is what gives the UL All-weather series its signature open, airy feel — the sense that heat is not trapped inside, but constantly escaping as you move.

The difference is in the nanofiber structure. While most waterproof-breathable membranes are film-based, Shield Air is built from ultrafine fibers layered like a web. The microscopic gaps between those fibers create pathways for air, physically releasing heat from inside the shell.

That is why Shield Air remains in the areas where ventilation matters most. Even with Pertex Shield Pro added to rain-exposed zones for greater protection, the Hoody keeps the breathability that makes it true all-weather activewear.

At 120g (Size S), the UL All-weather Hoody sits among the lightest 3-layer waterproof-breathable rain shells available.

And because it combines breathability with rain protection, it can take the place of both a wind shell and a rain jacket. One shell, fewer layers, less weight.

By removing the zipper, the UL All-weather Hoody becomes lighter, softer, and more fluid in motion — so natural you almost forget you’re wearing it.

Rainwear seams are usually sealed from the inside with seam tape, but over time, that tape can peel or weaken, creating a risk of water entering through the seams.

For the UL All-weather Hoody, we use ultrasonic welding instead. This process uses ultrasonic vibration to generate heat, melting and bonding the fabric without needle holes. It causes less damage to the fabric and helps reduce the risk of water entering through the seams after years of use.

Only a limited number of factories in Japan can perform ultrasonic welding at this level of precision. At our partner factory in Akita Prefecture, years of research and refinement have made it possible to combine the strength and waterproofness needed for hard use in the mountains.

Most rainwear provides a certain level of warmth by allowing moisture to build up inside the jacket. However, the UL All-weather series offers overwhelming breathability, which means the heat your body generates is continuously ventilated. Because of this, you’ll need to get creative with your layering when focusing on warmth, especially during rest periods.

To help, we’ve gathered layering suggestions for the All-weather series from Tomoya Tsuchiya (Hikers Depot), Kei Kuwabara (Run boys! Run girls!), and Yamatomichi Lab (Akira Natsume and Takahiro Watanabe), who collaborated with us on Yamatomichi Lab Special Issue: All-weather Activewear #3 – Tomoya Tsuchiya x Kei Kuwabara x Yamatomichi Lab Trilogy.

With the launch of the UL All-weather series, we created a special three-part feature in our JOURNALS series, Yamatomichi Lab.

This feature takes a deep dive into the technologies behind various waterproof-breathable fabrics, including Pertex Shield Air. It also includes real-world wear tests conducted at testing facilities, and a roundtable discussion with Tomoya Tsuchiya (Hikers Depot) and Kei Kuwabara (Run boys! Run girls!), exploring the current state of rainwear in the outdoor scene.

This series is not only a great resource for understanding the UL All-weather series but also an insightful look into the broader world of modern rainwear.

Sorry — here it is plainly, without the writing block:

• This product is an ultralight waterproof shell made with extremely thin waterproof-breathable fabric. Take care to avoid damage or tearing from abrasion against rocks, snagging on branches, or similar contact.
• Regular care is required to maintain waterproof-breathable performance. Dirt, sweat, and body oils on the membrane, the DWR finish, or the inner layer can reduce performance. Wash regularly according to the care label.
• Because the fabric is extremely light, thin, and porous, contact with products containing Vaseline, insect-repellent ingredients, or ethanol, such as hair cream, cosmetics, sunscreen, or insect repellent, may cause stains or reduce breathability.

Water repellency generally lasts longer on thicker fabrics because they can absorb more water-repellent treatment. The UL All-weather series, however, uses the thinnest, most breathable outer fabric possible to prioritize lightness and airflow. While the fabric has sufficient water repellency at the time of shipment, its durability is lower than that of thicker waterproof-breathable materials.

When the DWR is working properly, water beads up and rolls off the surface. As it wears down, water can spread across the fabric as a thin film, reducing breathability. This can make the inside feel damp from trapped moisture or condensation.

If water repellency starts to decline, wash the garment and apply heat with a dryer or hairdryer to help restore it. If it still does not recover, reapply a commercially available water-repellent treatment.

This product is designed for comfort during active use in relatively mild conditions, and as such, it offers less insulation compared to standard waterproof shells or winter hard shells. For this reason, proper layering is essential during rest periods or when additional warmth is needed. Please exercise caution when using this product in harsh environments.

For more details on layering strategies, refer to Layering methods at the top of this page.

• Machine wash cold, gentle cycle, at or below 30°C.
• Use rainwear detergent or a neutral detergent free of bleach, fabric softener, and optical brighteners.
• Wash separately or in a laundry net.
• For heavy stains, spot-clean with diluted detergent and a soft sponge. Do not scrub seams or seam tape.
• Tumble dry on low heat, up to 60°C, regularly to restore water repellency.
• Do not use fabric softener or bleach.
• Iron on low heat without steam.
• Do not dry clean.
• Products containing petroleum jelly, insect repellent ingredients, or ethanol may stain the fabric or reduce breathability. See Yamatomichi Journals’ “Yamatomichi Repair Department News #2: Cleaning Oil Stains from Rainwear” for cleaning tips.