I have travelled and lived in lots of different places, so the first thing I think is worth buying is a cashmere jumper. (It doesnt have to be new, (I have bought several over many years, always wash them carefully by hand and they last for years) The great thing about them is that they are very warm but extremely light. So I have old ones that I put in a plastic bag and shove in my rucksac and they are easy to carry , then if it turns cold or windy, you have the option to put it on, without it being heavy. Then , again I would go for a breathable but waterproof coat, and there are ones where you have a fleece that can be worn inside zipped to the coat or taken off. With those two things you will have a good variety to cover most weather conditions. Then I have very light insulate gloves, which I put in the pockets of the coats or jackets and an insulate style hat. That way outside it is easy to do simple adjustments by taking hat and gloves off, and having the very light jumper that you can put on and off easily. I used to be up Sweden and Greenland etc, and so tended to think a bit more about what I was doing in advance, so you might be in a department store or cafe where it is very warm. if you are then only going across the street I would just use the hat and gloves for that short walk, but anything more I would go into the ladies and put my jumper on. Dont forget about suncream and sunglasses too, if you are anywhere like that or have a hat with a brim , it is easy to forget you can get sunburn or rather windburn from winds over snow etc. Keep a little note in a book each night, to say whether you found what you had taken was good or not so good, and then if you go on another trip you will see what suited you best. Hope that is some help