When I was in a place called Ayr, Scotland, it's on the coast and I was there during the winter time and there was about close to 90 mile per hour winds and we rode bikes and as you could imagine that's probably not a good combination, it really wasn't. Like every hill that we tried to go up the wind would just hit us really really hard and we couldn't even go up the hill. Signs were falling off, it just really looked like a very mild hurricane.
The weather can be quite unpredictable sometimes, although, yes, it's very wet and very rainy. It's good to be prepared, like others have said. It can be one weather, like sunny one time, and then the next minute, rainy. It was one time, it was a little cloudy, it was fine, we were just walking along, it was a little cold, so we had our coats. But then it just suddenly started pouring buckets. Absolute buckets. So much so, I remember she was wearing little wellies, like rain boots, and I remember seeing water sploosh out of her boots as she walked. It was so wet. Everything got soaked. So one thing I do suggest is getting a waterproof bag, like a foldable, it clips together like a bag, to put whatever you don't want wet inside your backpack, because you'll need it, you'll want it.
It's a little more humid, and so the cold in Scotland is going to go straight through you unless you're wearing the right things. And so, it's just as cold as it gets in many places in the States, but it's a different type of cold, and the rain goes sideways, usually, because it's pretty dang windy.