Best jacket for Scottish Highlands in May?

Whichever brand you get, it's a good idea for it to be made of Goretex. You'll avoid that clammy feeling. I find Marmot to be a really good brand. Mine has zippered openings under the arms that you can unzip when it gets too warm.

My about 15 year old Patagonia "hard shell" is a 2.5 layer with Gore-tex membrane. The jacket has ventilation options including "pit zips". REI generic advice is a good starting point: https://www.rei.com/learn/expert-advice/rainwear.html

Because even the most breathable rainwear can get overwhelmed during
strenuous activity, almost all backcountry rainwear has pit zips
(underarm vents). Some jackets go a step further, having mesh liners
in torso pockets that can double as additional vents.

And of course layering is the key. On warm rain days, you can be walking with a light base layer (tee shirt) and rain jacket. Add insulation layers as needed. I carry my extra dry clothing in a light dry sack. Extra dry clothing include dry socks.

My Patagonia did well on the West Highland walk including one maelstrom rain day on Conic Hill. Jacket worked well but even with Gore-tex rain pants and gaiters, my socks get soaked on heavy rain days. And of course if it is sunny and hot, the jacket comes of and goes into my rucksack.

Having worn my way through a number of jackets and suffering the same breathability issues I ended up opting for a Marmot. It is very waterproof, windproof and excellent breathability and very lightweight, you can roll it up and place it in your bag and never know that it's in there.

Another vote for Marmot, their Pre-Cip jacket is water proof, has arm pit zips and allows air flow pretty well. I’ve worn mine in Scotland and Ireland with good results. Add a good fleece to go underneath and your good for any cold weather you might run into. Don’t skimp on your rain shell and it will last you many years.

Don't let the pricetag on some Goretex scare you off. Years ago when there's no way I would/could spend that kind of money on a jacket, my in-laws gave me the LL Bean long one that covers your rear end for Christmas. It fits into its own pocket so was easy to carry in my purse on a day in 2015 when it was pouring rain in St. Fagans park in Wales where it kept me dry, even when I sat on wet benches. So be sure to get the longer one not the short jacket length. Because of the breathability, I also wear it during downpours during the summer in Alabama.

I'd make sure that in addition to being waterproof, for Scotland it ought to be windproof as well, so not ultra ightweight. As I've discovered from bitter experience, being wet is OK (although not desirable!), but it's the wind that makes you cold. And Scotland can be windy in the Highlands at any rate.

So I would lash out on a Goretex shell and layer up (or down accordingly) as the conditions required. You can get fairly lightweight jackets in Goretex, but my old lightweight jacket is waterproofed pertex and yes, while not much got through rain wise (while it worked - I discovered recently it doesn't, but it owes me nothing), nothing got out so you could get hot quickly if putting in any effort. While the much vaunted Goretex is supposed to breathe, it depends on the individual and the effort being expended as to how 'breathable' it is, as there is a point when you are heating up quicker than the Goretex can transport the heat and internal moisture out.

That said, I wouldn't go ultra lightweight for Scotland as even in summer as the weather can occasionally be quite unpleasant - being so near the sea on this island rain is usually not only wet but cold with it, especially if driven by the wind.

That said, I've had some spectacular days in the Highlands when a waterproof jacket has been the furthest thing from my mind, but it was always there in my backpack, just in case! Always better to have and not need than to need and not have!

There's some excellent advice above so you should have something to go on which will help you make a decision.

Have a great trip!

Ian

PS. While I'd hope never to have to use them, I'd pack a pair of waterproof overtrousers too, even if they were a cheap pair, which you'll be unsurprised to learn there plenty of and readily available from most outdoor shops in Scotland, so you could 'invest' in a pair when you get here, having determined by looking outside/viewing the weather forecast as to whether you think they might be necessary. Fingers crossed they aren't!

A quality hooded jacket is a must...though none work perfectly. Use lighter layers of clothing beneath and if in active pursuits, assure adequate ventilation. In your situation, I'd also pack soft, lightweight, merino wool products (for example and shop carefully as retail prices are very high, Icebreaker, SmartWool and comparable brands) including t-shirt, zip-t sweater and yes, even boxers/briefs. Wet cotton against skin on a cool day while hiking in the rain and with wind....ugh. Also, avoid pants made of cotton and instead, wear ones made of Supplex nylon. Lightweight, easily packable, rain pants is also a good idea. Enjoy your trip.

Marmot PreCip wear are good values. The downside of PreCip garments is the stiffness of the fabric. Garments tend to make noise while walking/moving.

Rain pants. My rain pants have full size zips to allow pant to be put on without taking my boots off. Side zip needs to be protected with a Velcro storm flat. The size zips are likely the vulnerable point of entry for wind driven rain, but better than sitting down to take off boots to get on rain pants as rainfall intensifies.

My Patagonia garments are expensive but well designed and cheap in the sense that they are close to new after 15 or so years. (I do save them for expedition wear and don't use them for around town use). And remember that a cheap garment that fails when you need it the most is a bad buy.

Thank you all so much for the quick and thoughtful responses! I'm going to need to swing by REI and choose between the Marmot Precip and the Marmot Minimalist. Cheers!

Your honeymoon sounds idyllic - have a wonderful time!

Oh good, I am glad you are going in person to see the jackets! The different brands do have different cuts and feels. I just gave my Marmot Precip away because it was just cut to slimly to accommodate even a small purse zipped up underneath it. Make sure yours is roomy enough for layering.

The one I've got now is a Cabela's brand and I like that it is a roomier cut and softer, less noisy fabric. It is totally waterproof and yes, tour tested, hahaha!!

Usually REI staff are well informed about their products too so don't be shy about asking questions.

It does not have to be actual “Gore-Tex”. The main Gore patent expired in 1997 and now there are a number of other highly effective (waterproof and breathable) membrane systems out there. Major companies like Patagonia (and probably Marmot) mostly use their own proprietary technology, and most are excellent. But you will sweat in any of them if dressed too warmly underneath.

Backcountry.com has an amazing variety of waterproof breathable “technical shell” jackets, a few on sale right now for $120 or less.

I have a waterproof raincoat from Eddie Bauer and love it; not sweaty at all.

I've been able to use my jacket several times since purchasing, wanted to report back! I went to REI intending to try on both the Marmot Precip and the Minimalist. The Precip was more of a rain shell than I was expecting (but had been fairly warned) and boy was it LOUD. Not the colors or styling or anything like that, just plain old crinkly and loud. I couldn't take it! The Minimalist seemed to be popular, as there were only a few left in the store. It was pretty good, no real issues or concerns with it but I just didn't feel as pulled to it as I'd hoped. And then... I found the Marmot Lea. This one is slightly longer (I'm very short, but it isn't ridiculous on me - excellent length for bum coverage if sitting on a damp bench), is light and breathable but still a great waterproof jacket, plus I found it in a beautiful bottle green color - and it was on sale!
We've had some unusual weather here in Houston, and I've been able to use this jacket pretty regularly this winter. It's plenty comfortable on its own or over a hoodie, doesn't make me sweaty and still definitely waterproof! The only thing odd about it is how deep the hood is - if I have my hair in a bun it's not an issue, but if my hair is down, the hood sits so far forward that I have to physically lift the top/sides to see properly. If it was driving rain, I guess this would be fine? The hood itself can roll up/velcro into itself, making kind of a thicker collar. I've just left it down and accessible so far.

Oh, and my fiance ended up with a Mammut Wenaha jacket. He's been very happy with it!

Thanks for everyone's input!!

LAYERS!!!! We will be in Ireland and Scotland in mid May. I will bring what I brought to England in April of 2016. Patagonia Nanopuff zip up hoody, Patagonia Nanopuff zippered vest, and an REI water proof zippered and snapped rain jacket with a hood. My husband brings the same. Then we each have one polar fleece pullover - I love the Better Sweater also by Patagonia but Kuhl and REI have great options too and always check Costco for some great deals in comparable clothing. The two Patagonia Nanopuffs, the vest and zip up hoody, can be layered and make sure the rain jacket fits over. You can put the polar fleece layer under it all if needed. It works amazing and you will be warm and dry. The Nanopuffs have an interior pocket the entire garment can be stuffed into. They pack super tight and take up minimal space. You can then remove each layer as needed if weather invites less clothing! :-) Lastly, we travel really light so in my carry on, all of my clothing is the same color scheme so all mix and match and goes together.