SWEATER VEST
Right before the end of summer is, in my opinion, one of the best times for wearing whatever it is that you want. Sure, you might be a little too hot or too cold at times, but it's the time of year that, aside from winter coats, nearly anything goes as far as wearability is concerned.
It's also the best time to get full use from any sleeveless sweaters you might own - which in my case apparently, is a strangely high number...
xx,
Tienlyn