What plant hardiness zone is Whitehorse

Whitehorse is located at Yukon Territory (YT), Canada.

Plant hardiness zone (winter frost zone or gardening zone) for Whitehorse is 1b by the PHZ Canadian scale.

Also perennial plants from the equivalent USDA zone 0b with coldest winter temperature −53.9 … −51.1 °C and lower can be grown here.

Whitehorse, Yukon Territory @ wikipedia.