It's because Environment Canada operates official weather stations in Harrow and Erieau…..Local 4 doesn't realize how few people live in those places though. Environment Canada also operates a weather station at Windsor airport, by far the largest population centre in the region.

I've been watching and I still don't see Windsor on the map despite it being the 2nd largest city in the region. They still have the tiny village of Harrow on it for some dumb reason and they are still doing that useless and time wasting 4-zone forecast.