There's actually a number I would take over 1880. That would be incredibly destructive. At any rate I think a really cold winter is probably more possible than something like that in this post little ice age climate. The setup required to make another January 1880 scenario would be very hard to pull off. That event had 2 sub 29.00 lows take the dream track for Seattle snowfall, and fed in enough cold air to allow about 5 inches of water equivalent to fall as snow at sea level.
Even in 2010 we had a heat wave start on July 6th.
Given that we have another 5 or 6 sunny days ahead after Monday... this June has been significantly better than June 2010. Current cold trough notwithstanding.
Just went trail running and skiing with a couple buds, pretty crazy snow for mid June. Can't remember the last time I got powder (well more like cement) turns as low as 6500 feet in mid June. Will certainty be back up tommorow.