What biome is used to classify the coldest climate in North America?

The biome that classifies the coldest climate in North America is the tundra. Characterized by its harsh, frigid temperatures and minimal precipitation, the tundra features a short growing season and is predominantly found in Arctic regions, such as northern Alaska and parts of Canada. This biome is marked by permafrost, which restricts root growth and limits vegetation primarily to mosses, lichens, and low shrubs.