[mikrl]

Ontario is culturally 2 provinces, southern and northern Ontario.

The north is what you normally think of Canada: rocks, trees and lakes. The south is similar to the neighbouring US states of Michigan, Ohio, and New York but with a distinct Canadian identity and a French region in the east.

Most of the population (13.4M) lives in the southern part (114,000 km^2)

[haldujai]

Still a bit too general.

Southwestern Ontario (Windsor/London) is very culturally and demographically different from Toronto/Golden Horseshoe and Eastern Ontario (Ottawa/Kingston)

Michigan is also culturally different from New York.

[mikrl]

The north-south split is the most striking, but yes south can be further divided into the GTA, SW (farm country and a small part of the rust belt, similar to the Midwest) and eastern (Ottawa and the townships: government and farms)

Michigan and Ohio are most similar to SW but upstate NY also bleeds culturally into the region, both around Niagara and the thousand islands.

[haldujai]

North-South seems like an arbitrary reduction of Ontario culture.

I don't know that someone Thunder Bay/Sault Ste Marie is that culturally different from Barrie/Sarnia. Windsor to Ottawa is very different.

That 90% of Canadians live within 100 miles of the border seems minimally related to culture differences and more geographic/economic.