Based on a Google search on butterflies, I believe it's a Mourning Cloak (Nymphalis Antiopa) a cold-tolerant native which is one of the first butterflies to emerge in spring. The mourning cloak spends the winter hibernating in loose tree bark or other hiding places where it is protected from winter's wind. Their larval host plants tend to be trees and shrubs rather than flowers, dining on tree sap more than nectar. The mourning cloak has been spotted flying around as early as March in Manitoba. Brrrrr!