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Personal: Residential


Climate Zones – ENERGY STAR®

There are four climate zones in Canada (A, B, C and D), based on an average annual temperature indicator called a heating degree-day (HDD).

An HDD is the annual sum of the degrees of the average daily temperature for all days below 18°C. This accumulated sum is averaged over a 30-year period to provide a good indication of the average temperature in a given location. The higher the average HDD value, the colder a location and the longer the heating season.

Zone A is the mildest, and Zone D is the coldest. Colder areas require windows, doors or skylights that are more energy efficient. Homes and apartments in colder locations are likely to require less air conditioning.

The climate zones for which a window, door or skylight is ENERGY STAR qualified will be shown on a label and in the sales literature.

To buy an ENERGY STAR qualified window, door or skylight:

  • locate the zone that you live in
  • select a product that is ENERGY STAR qualified for that zone

Note: you may click on a province or territory on the map below to obtain a more detailed view.

Climate Zones
Map of Canada's climate zones

Many window, doors and skylights qualify for more than one zone in Canada. The more zones a product qualifies for, the more energy efficient it is. So you can save even more on your energy costs by purchasing a product that is qualified for a zone that is colder than where you live.

If you live in a location that is significantly higher in elevation than the surrounding area, get a product rated for a zone at least one level colder than indicated on the map. This applies especially to areas in southern and central British Columbia, where energy efficiency levels have been determined for major urban centres that are normally located in valleys.

  • Zone D: > 8000 HDDs
  • Zone C: > 5500 to <= 8000 HDDs
  • Zone B: > 3500 to <= 5500 HDDs
  • Zone A: <= 3500 HDDs

HDD values for each of Canada's climate zones

Nunavut Northwest Territories Yukon Newfoundland and Labrador Maritimes Quebec Ontario Manitoba Saskatchewan Alberta British Columbia