Canadian universities first look at your junior year grades. If those aren’t sufficient to admit you, they wait for your first semester senior year grades, reassess and then to decide to admit or wait for your second semester interim grades and so on.
A 3.4 unweighted GPA would be about the minimum I would recommend applying for less competitive programs at U of T or McGill. For those programs a 28 ACT may be sufficient. For more competitive programs like engineering/commerce/computer science, 3.7 GPA and 30 ACT would be the minimum.