I'd never complain to a Scotsman about the weather. Haven't been there myself, but I did see Trainspotting. And I've spent a couple dreary winters in Oxfordshire - I imagine Scotland is like that, only drearier.
It's normal here in the Pacific Northwest for summer to end quite abruptly, switching from warmth and sunshine to cold and rain in a single day. And then the sun doesn't come back until June. But that normally happens in mid- to late-October. I can't recall that ever happening before the calendar end of summer. It's the end times for sure.