This is a really interesting thread! I am pretty much in line with Suz, or as my Mom used to say, the only thing she learned about Canada in school was in Gaelic:
An-fhuar sa gheimhreadh, an-te sa samhradh - "very cold in winter; very hot in summer". How succinct was that geography lesson!
We barely have transitional weather; it just swings wildly from cold to hot before settling in for the winter or summer season.
To me, transitional dressing (the most fun kind) is what I'd define as "seasonally confused lite" - booties but without thick socks, blazer and jeans with slides, shorts and a light sweater with sneakers. And layers, which I avoid in both summer and winter - too hot in summer and too bulky under a puffer in winter!