A couple of days after I responded to your first post in this thread, I started chatting with a couple of Indian immigrants who often lunch at the same place I do (in Dayton, Ohio, about 700 KM southwest of Toronto). With your question in mind, I asked how long it took them to acclimate to our winters. The first guy used the exact words I did: "it was unimaginably cold."

My first spring in Toronto (which was forty, not thirty years ago -- time flies!) had highly variable weather. I remember that it was 85 degrees F (29.5 C) on May 5th, but we had five inches (13 cm) of snow on the 15th. I was a student and spent a lot of time outside, either walking, waiting for buses, or simply enjoying the fresh air, so I made sure to dress warmly.