I live in Vancouver, so there's a pretty wide variety of habitats around here, but mostly water, forests, mountains, and cities, (not to mention we have a few fossil deposits in B.C, so fossil pokemon aren't out of the question.)
There would probably be water, grass, bug, flying, rock, poison, electric, normal, steel (maybe,) ice types in the winter, and maybe the odd fire or ground type if you go a little further inland in the summer.
From this, I can conclude that my mons would probably be Magneton, Roselia, Seadra, Glaceon, Quilava, and Anorith.
Also, out of curiosity, what would be the natural environment for psychic, fighting, dark, and dragon types?