I've done some hiking in Scotland.

Unless you keep to the east coast, I can assure you that won't be "slogging around in the rain now and then".

It doesn't rain constantly, but if you're hiking in it for several days you may think so. It can be pissing with rain, spitting rain, or a Highland mist. You'll soon understand why UK residents make such a big deal of cloud-free days.

Bring the latest and the greatest rain gear you can get - full rain suits too.

Of course rain is part of the charm of the Highlands. Hiking up a hill into a rain cloud is an experience everyone should have.

Slan yall,
steve