What to wear?

I would layer. I have been to Scotland years ago and Ireland a few years ago, middle of July and the end of June respectively. I would bring at least one pair of jeans, ( I don't generally wear jeans in Italy) but for Scotland, they work . I would bring two pairs of shoes, one pair being sneakers and if you want to bring the hiking boots. Remember, the hiking boots are heavy and you carry your own luggage. I would bring a rain jacket and a hoodie. When in Ireland, I wore a long sleeve blouses, a thin hoodie and a casual blazer and then the jacket. I am always cold and that kept me warm. Maybe one sweater if not the hoodie. And a scarve, not wool, but something to keep your neck warm, but pretty that you can wear with a blouse or sweater. Again, if you decide to bring a short sleeve tee's or blouses, make sure you have a hoodie or sweater. The weather will start out cool, may get warm, then turn cool again in the evening. No dresses, shorts or capris or sandals. More rugged and outdoorsy type of tour than France or Italy. Pubs more so than fine dining, but still good food and fun.

On our last trip, we were in the Alps in Switzerland but also through Italy, so I had to pack for all weather types since the forecast for Switzerland was colder than normal for September. A couple of items that really kept me warm but also took no space: a black very thin thermal top and a pair of grocery store tights. I wore those under layers in Switzerland and could take either of them off in a bathroom & stick in our small daypack as the weather changed during the day.

I was in Scotland the first week of June last year. It rained most days, sometimes off and on several times; not hard enough to wash out an activity, if one had (as I did) good rain protection. I would strongly recommend an umbrella besides a rain shell. Besides the shell I had a down vest which, over a long sleeve shirt, was perfectly comfortable temperature-wise.

BTW, Euroschirm is a really good German umbrella; lightweight and durable.

I took only a pair of Clark's Wave shoes, which are waterproof, and had no footwear problems, even on (modest) hikes.

Jeans, blouses/tops, sweaters, a lightweight lined weatherproof jacket, rain hat, umbrella, and warm socks. It is going to rain! It might get warm in the day but you'll likely need a light lined waterproof jacket when it does and nights can be chilly.

I much prefer a rain coat with hood instead of messing with an umbrella. I basing that on 3 trips to Ireland and one to Scotland,,,,, if you wear capris at home, you might try one pair of jeans & one of capris......however, if you live in the south USA, you are used to a significant amount of heat, so you might chill easier.

This worked well for us. Take your usual Summer clothes (light shirts, etc.). Then, take a high quality, hooded raincoat and a zip-up fleece vest or jacket to wear with or without the raincoat. It's worth investing in a very good raincoat - no cheapie ponchos. Get a coat that can compact down in either a pouch or its own pocket. I would not wear jeans; if they get wet, they take a while to dry out. I took both "sensible" black shoes and day-hiking boots with smartwool socks. After one day with the sensible black shoes, those shoes stayed in my suitcase. Next time, I will only take the light hiking boots with the smartwool socks (wear them over).

Just to add to everyone else, I would buy a good, light weight raincoat that is "waterproof" not water resistant. I like the Marmot Pre-cip, it is excellent and reasonable in price, Patagonia and Columbia also make good "waterproof" jackets, I cannot stress enough the importance of waterproof instead of water resistant. The next item is a good fleece (either a pull over or zip up)
because with a good fleece and rain jacket you will be comfortable down to 40 degrees, it will allow you move around and enjoy the day's activities instead of being kept inside. My favorite fleece's are Patagonia Better sweater, Columbia Heat 360, Kuhl and etc. Yes, these types of clothes are expensive but if you watch the internet sites (Sierra Trading post, etc.) you wil be able to buy them for 30-50% off. There are 3 things a traveler needs to be willing to invest in:
1) Good waterproof jacket
2) Good fleece jacket/pull over
3) A good carry on bag with or without wheels

You will use these items for many years and on many trips so choose wisely!

As you can see from the above list of weather-related clothing items, you may not be able to get them all in a carry-on.
It really is okay if you find you have to check a bag. Better that than leaving clothes out that you wish, on the trip, that you wish you had brought.

Thanks everyone for your advice. I already have a nice rain jacket I got at Bass Pro Shop. I just want to ask Barb what kind of pants did she wear instead of jeans?

I wore capris and khaki's. No shorts. Scotland is a place to keep the knees covered. I wore "dress" t-shirts and polo type shirts. I wear stuff that's easy to launder and can roll up into a packing cube. V-neck cotton blend shirts, etc..

Scottish weather is changeable and regional. If you are there for a week you will likely experience some rasin and some blue sky dayts. Weather on Highland peak will likely be different than weather in a southeastern city.

You can check climactic averages of locations you plan on visiting then expoext wetter days and dryer days. And keep in mind that in Scotland there is no bad weather, only bad clothing for the conditions.

Our one trip took place in May several years ago and we seemed to experience everything but snow and temperatures were moderate. Rain gear, light jacket/sweater to short sleeves and sun glasses/hat.

I was in Scotland in midJune and wore turtle necks and the same wool sweater with a raincoat every day. Be prepared for cool weather.. Or else budget $$ for a sweater from Scotland as a souvenir. Have fun!!