Atlas of Canada - Plant Hardiness Zones
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Description
This 4th edition Plant Hardiness Zones map shows updated zones related to perennial plant survival in Canada. The map is based on a formula using seven climate variables that influence plant survival:
- Monthly mean of the daily minimum temperatures of the coldest month
- Mean frost-free period above 0°C in days
- Amount of rainfall from June to November
- Monthly mean of the daily maximum temperatures of the warmest month
- A winter harshness index related to rainfall in January
- Mean maximum snow depth
- Maximum wind gust in 30 year period
The original map was developed by Agriculture and Agri-Food Canada in the early 1960s based on average climate values from 1930 to 1960. This new map uses 1991 to 2020 averages.
The development of this map was made possible through a collaborative effort by scientists at Natural Resources Canada’s Canadian Forest Service, Environment Canada, and Agriculture and Agri-Food Canada. Read about the updates to Canada’s plant hardiness zones in the Simply Science article, In the zone: Canada's plant hardiness zone maps and website get an update.