We have had it rather easy so far this fall. Temperatures have been reasonable and many spots still have not hit 32 degrees yet...however, that may change come Saturday morning in some spots.
Cold is building in northern Canada and is deepening, getting colder. Losing the sun angle means that these cold shots of air can move into the lower 48 rather easily now and new computer guidance shows a major invasion of cold Canadian air sometime next week in the northern Plains, possibly going as far down to north Texas with freezing conditions.
Denver snow? Possible. Things look to change dramatically after the Columbus Day "heat" with highs in the 70's. The nation could be transitioning into more of a late fall or early winter pattern as many places in the North could be seeing their first snow of the season. Something to watch, but it will certainly be getting much colder in the weeks ahead, no matter what.