Why are the ports of northeastern Canada closed for about half of the year?

The ports of northeastern Canada are closed for about half of the year primarily due to harsh winter weather conditions, including ice formation in the waterways. The extensive ice cover makes navigation dangerous and often impossible for ships, leading to seasonal port closures. Additionally, the extreme cold can hinder port operations and infrastructure. Consequently, shipping activities in this region are largely limited to the ice-free months of late spring through early fall.