The OEX Aonach II is a budget mountain jacket with a stretchy 70D two-layer shell, a YKK AquaGuard front zip and a fully adjustable wired hood, all for under £100. It’s a waterproof jacket built for hill days and wet dog walks alike.
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I purchased the OEX Aonach II Waterproof Jacket for review. All opinions are my own.
- Weather Protection
- Breathability
- Comfort & Fit
- Weight
My Verdict
A mid-weight mountain waterproof at a budget price. From my experience with the OEX Aonach II, it keeps the rain out, the pit zips do a lot of the heavy lifting on breathability, and the longer mountain fit is excellent with a backpack on. It isn’t the lightest or most packable shell around, though. At under £100, I’d say it’s one of the better-value waterproof jackets you can buy for UK hillwalking.
Pros
Cons
Where to Buy
OEX Aonach II
My Verdict: “A sub-£100 mountain shell that keeps rain out, covers you under a backpack and dumps heat through pit zips.”
Women’s version (OEX Fortitude II) also available at
Go Outdoors, Blacks and Amazon.
The Aonach II is the updated version of OEX’s Aonach waterproof. OEX classes it as a mid-weight jacket, and it sits towards the more technical end of their waterproof range, with a mountain fit, a wired hood and pit zips you’d usually find on pricier shells. The big changes from the original are the stretch outer fabric and the YKK Vislon AquaGuard front zip. I tested the men’s version in black, size small. It also comes in red and in sizes XS to XXXL, and the women’s equivalent is the OEX Fortitude II.
Full Specifications
Price: £100
Weight: 640g (size small, my measurement)
Waterproof rating: 9,000mm hydrostatic head
Breathability: 10,000g/m²/24hrs
Construction: 2-layer 70D stretch shell, taped seams
Fit: Mountain fit
Sizes: XS to XXXL
Colours: Black, Red
Outer: 88% polyamide, 12% elastane with PFC-free DWR / Lining: 100% polyester, mesh and taffeta / YKK Vislon AquaGuard centre front zip with internal storm guard / Fully adjustable mountain hood with stiffened wired peak / Underarm pit zips / 2x water-resistant zipped hand pockets / 1x water-resistant zipped chest pocket / 1x internal pocket / Fleece chin guard / Adjustable cuffs / Adjustable dropped back hem with dual tether drawcords
How I Tested It
Autumn is settling in across East Sussex, the paths on the South Downs are getting muddier by the week, and a waterproof is back to being the first thing I grab on the way out the door.
I’ve been wearing the OEX Aonach II on walks across the South Downs and on dog walks closer to home, mostly with just a T-shirt underneath. I also decided to put the jacket through a stress test by standing beneath the shower for five minutes to simulate a heavy downpour, and checked what got through. Here’s how I’ve got on with it.
Is the OEX Aonach II Waterproof?
Yes, the OEX Aonach II is waterproof.
OEX rates the fabric at 9,000mm hydrostatic head. Put simply, that’s how tall a column of water the fabric can hold back before it starts to seep through. 9,000mm is a solid figure for everyday UK hillwalking, though it’s well short of premium shells. The 3-layer Rohan Aira I’ve tested is rated at 34,000mm, but it costs three times as much. Interestingly, the original Aonach was rated at 10,000mm, so the new version has dropped slightly on paper, presumably as part of the switch to the stretch fabric.
The outer fabric also has a PFC-free DWR (durable water repellent) finish. That’s the coating that makes rain bead up and roll off the surface, so the fabric doesn’t soak up water and start to feel heavy and clammy. PFC-free means it’s made without the “forever chemicals” older DWR treatments relied on.
What does two-layer mean?
In a two-layer jacket, the two layers are the outer face fabric and the waterproof membrane bonded to the inside of it. The lining is a separate fabric that hangs loose inside the jacket; on this one, a mix of mesh across the back and smooth taffeta elsewhere. It’s there to protect the membrane from sweat and rubbing, and it makes the jacket nicer to wear over a bare T-shirt.
It’s a different approach to the 2.5-layer Mac in a Sac Ultralite I’ve reviewed, which prints a thin protective coating (the “half” layer) onto the membrane instead of using a lining, and to 3-layer shells like the Aira, which bond a third, protective fabric directly to the inside of the membrane. Two-layer jackets are usually comfier and cheaper, but heavier and bulkier.
The seams
The seams are taped, which stops water creeping in through the stitch holes. One of the downsides of being lined is that you can’t see the state of your sealed seams, and you can’t treat them as the jacket ages. With an unlined shell, you can spot a peeling seam tape and fix it. With the Aonach II, you’ll only find out when you feel it. That’s the trade-off for the comfort of a lined jacket.
The zips
The Aonach II uses a YKK Vislon AquaGuard zip. Vislon zips have chunky moulded teeth, rather than the smooth, rubbery look most people picture when they think of a waterproof zip. The waterproofing comes from the coated tape on either side of the teeth and from the internal storm guard behind it.
The pockets back that up. There are three external zipped pockets, a hand pocket on either side and a chest pocket on the left, plus an internal pocket on the right sealed by a Velcro tab.
Care for your gear
Nikwax TX.DIRECT Spray-On Waterproofer
From £15 • 500ml
A quick spray-on reproofer that restores the DWR on water-resistant jackets. PFAS-free, water-based, and no tumble dryer needed.
Is the OEX Aonach II Breathable?
The fabric itself is moderately breathable, but the pit zips are what make the Aonach II comfortable when you’re working hard.
OEX quotes a breathability rating of 10,000g/m²/24hrs. That’s respectable rather than outstanding, and a lined jacket like this will always hold a bit more warmth than a stripped-back shell. The mesh panel across the back helps here, as that’s where most of the sweat builds up under a backpack.
The pit zips are the standout. It’s amazing how much of a difference they make when you’re getting hot and sweaty climbing up a hill. Each underarm zip is two-way, so you can fine-tune the adjustments to get just the right amount of airflow.
Comfort and Fit
The mountain fit is my favourite thing about the Aonach II. OEX describes it as being cut for freedom of movement “while still allowing room for layering over a midlayer”. In practice, that means a longer back that covers your rear, arms that don’t ride up when you reach, and space underneath for an extra layer.
The longer back is especially useful with a pack on. When you’re hiking up a hill with a backpack on, the hip belt and shoulder straps tend to drag a shorter jacket upwards. The Aonach II keeps you covered. There’s a drawcord toggle on either side of the hem, so you can tighten it around your waist and stop it riding up in the wind.
I’m 163cm and wore a size small, and I found the sizing accurate. On most of my outings I’ve worn just a t-shirt underneath, but there’s plenty of room to fit a thicker fleece or an insulated layer like the OEX Kintra down jacket I reviewed last winter.
The hood is excellent. A wired peak and three toggles let you adjust the fit, so you can pull it in close when the wind picks up and still see where you’re going.
There are a couple of downsides around the hood, though. There’s no soft fleece patch around the chin, so when you zip the jacket up fully, the bare fabric rubs against your face. A soft lining around the collar would make long, wet days more comfortable.
The toggle releases are also sewn inside the fabric of the hood, which makes it a bit fiddly to release the cord when you want to open the hood back up.
Weight and Durability
The Aonach II is a mid-weight jacket, and my size small weighs 640g on my scales. Rolled up into its hood for storage in my pack, it’s about the same size and width as a 1L Nalgene bottle. It goes in a daypack without fuss, but the lining and the 70D fabric mean it takes up more space than a 2.5-layer shell. If you want something to stuff in a running vest or a bum bag, this isn’t it.
It’s early days, but the build quality is reassuring for a jacket at this price.
The 70D stretch fabric is a big part of that. The D stands for denier, a measure of how thick the yarn is. Ultralight shells often use fabrics in the 10D to 30D range to save weight, so 70D puts the Aonach II towards the burlier end for a waterproof. You can feel it straight away: the fabric is noticeably thicker than the ultralight shells I’ve tested, and it should be hardier against rucksack straps, brambles and rock as a result. That’s part of the reason it weighs 640g.
There are a couple of nice touches too. Small reflective patches on the front and back (the logo on the left breast and an X between the shoulder blades) help you get seen on the roads. I was testing the black jacket, which is obviously going to be hard to spot in the dark, but these small details help. There’s also an internal and an external fabric loop to hang the jacket up.
Alternatives to the OEX Aonach II
If you want the best possible waterproofing and the lowest weight, the Rohan Aira is a 3-layer shell rated at 34,000mm that weighs 260g, but at £300 it’s a very different price bracket. For running or fast hiking, the Mac in a Sac Ultralite is a 2.5-layer jacket at 240g and around £75. It’s lighter and packs smaller than the Aonach II, but it doesn’t have a lined interior, a wired hood or a mountain cut. If you’re after a Gore-Tex jacket and have a bigger budget, my guide to the best Gore-Tex jackets covers the premium end.
Should You Buy the OEX Aonach II?
Yes, if you want a mountain-style waterproof without paying mountain-brand prices.
It suits hillwalkers, day hikers and dog walkers who want a jacket that keeps the rain out, keeps them covered with a backpack on and leaves room for a fleece underneath. If you’re asking whether OEX jackets are any good, this is a strong answer. Between this and the Kintra, OEX keeps getting the basics right at a sensible price.
If weight and pack size are your priority, a 2.5-layer jacket will suit you better. If you’re heading into the mountains in serious winter weather, it’s worth spending more on a 3-layer shell with a higher waterproof rating.
At under £100, the Aonach II is excellent value. You can find more of my jacket reviews in the clothing and footwear reviews section.
Where to Buy
OEX Aonach II
My Verdict: “A sub-£100 mountain shell that keeps rain out, covers you under a backpack and dumps heat through pit zips.”
Women’s version (OEX Fortitude II) also available at
Go Outdoors, Blacks and Amazon.
Related Guides & Reviews
The resources below cover the basics, common questions, and related kit to help you get more out of your time outdoors.
- Best Waterproof Jackets for Hiking in the UK
- Best Waterproof Hiking Boots UK
- Berghaus Maitland GORE-TEX Overtrousers Review
Steve Cleverdon
Adventure-driven outdoor gear reviewer and paddleboarder, Steve has spent 20 years exploring rivers, coastlines, and trails across Britain and abroad, sharing what he’s learned along the way. Learn more about Steve or get in touch.
