While not the Polar Vortex of yore, it's definitely colder in Chicago now, even a little below normal. In any event, Wednesday and yesterday were the first two days that failed to get above freezing since March 4th and 5th, 253 days ago.
And it snowed yesterday. Again, not horribly unreasonable for mid-November, but not entirely common, either. But nothing so far suggests that our mild summer will be followed by a really cold winter; and in fact, the long-range forecasts are pretty normal.