Hardiness zones, also called growing zones or planting zones, show which plants can survive the winter in a given place. The zones on this map are Canada's plant hardiness zones for 1991 to 2020, published by Natural Resources Canada in 2025. Canadian zones combine several climate measures, including winter low temperatures, the length of the frost-free season, rainfall, snow cover and wind, so the temperature range shown with each zone, its extreme minimum winter temperature, is a guide rather than the whole definition. The previous edition, based on 1981 to 2010 data, is still available: Northwest Territories hardiness zones, 2010 edition.
Under the 1991-2020 zones, Northwest Territories spans 6 hardiness zones, from zone 0a (-56.7°C to -53.9°C) to zone 2b (-42.8°C to -40°C). Of the 10 cities and towns listed below, 6 are in zone 0a, the most common zone. Yellowknife is in zone 1b, Hay River is in zone 1b, Inuvik is in zone 0a.
| Location | Hardiness Zone (1991–2020) |
|---|---|
| Akłavik | 0a - -56.7°C to -53.9°C |
| Behchokǫ̀ | 1a - -51.1°C to -48.3°C |
| Délı̨nę | 0a - -56.7°C to -53.9°C |
| Hay River | 1b - -48.3°C to -45.6°C |
| Inuvik | 0a - -56.7°C to -53.9°C |
| Norman Wells / Tłegǫ́hłı̨ | 0b - -53.9°C to -51.1°C |
| Paulatuk | 0a - -56.7°C to -53.9°C |
| Sachs Harbour (Ikaahuk) | 0a - -56.7°C to -53.9°C |
| Ulukhaktok | 0a - -56.7°C to -53.9°C |
| Yellowknife | 1b - -48.3°C to -45.6°C |