I never go by those dates, if you go by that, Winter starts in like December. December is more like middle of winter weather wise. :biggrin:
Not sure who came up with those dates. Fall and spring are basically transitional seasons as well, they need to be much shorter. Way I see it is:
September 1: start fall
October 1: start winter
May: start spring
June:start summer
That would make more sense and match the weather a bit more.
Though I'm surprised, the leaves did not really start changing color yet. I see the odd yellow leaf on the ground though but not more than that.