Many times this is actually not true and because Canada is North of the US many people think this. Much of Canada even in the prairie provinces stays much warmer than Minnesota. Minnesota is about as far away from an ocean that you can get and when you get a polar vortex that comes straight down from the Hudson Bay it will usually cause temps in Minnesota to be colder than even across the border to the North in Canada. Looking at temps right now it is warmer North of the Hudson Bay than it is in Northern Minnesota.