Extreme heat will continue to be a problem in Canada. The number of days above 30°C is expected to double or even triple in some parts of Canada between 2021 and 2050.
Toronto alone could eventually experience 59 days a year above 30°C, compared with a historical average of just 13 days.
Sources: Health Canada — Guidance on Upper Indoor Temperature Limits
Health Canada — Adapting to Extreme Heat Events
Heat Extremes, Valuation and Financing
We tend to think about a house in terms of its location, size, condition and price. But two houses sitting on the same street can provide very different experiences during a heat wave. One might have central air conditioning or a heat pump, good insulation, efficient windows and plenty of shade. Another might have the exact opposite making it difficult to cool.
If hotter weather becomes increasingly common, these differences could become more important to someone deciding which house to buy. For starters, heat concerns can mean higher electricity consumption.
Instead of asking “How much does this house cost?” home buyers may focus on the question also “How much will it cost me to upgrade and maintain this house during heat waves?”
Two similar houses in the same neighbourhood may have different heat resistance. If buyers recognize that difference they may incorporate future costs into the house price. Suddenly extreme heat could affect property values.
It’s practical not theoretical
This isn’t entirely theoretical. Governments and homeowners are already spending substantial amounts of money improving how Canadian homes use and manage energy.
As of February 2026, more than 406,000 Canadian households had completed retrofits through the federal Greener Homes Grant, with $1.8 billion in grants issued. Heat pumps were the most popular improvement, with 229,000 installed through the program. By comparison, in June 2024, about 240,000 households had completed retrofits and approximately 136,000 heat pumps had been installed, meaning both figures increased by roughly 70% in less than two years.
2026 source: Natural Resources Canada — Greener Homes Initiative Progress Update
2024 source: Natural Resources Canada — Canada Greener Homes Grant at a Glance
Extreme Weather and Mortgage Lenders
When a lender gives you a mortgage, they’re interested in your ability to make the payments. But they’re also lending money against an asset: your house.
The property is security for the mortgage. That means anything capable of materially affecting its value or marketability is of importance to the lender.
Here is an example of extreme weather events and Canadian Lenders’ reactions. Bank of Canada researchers have studied how flooding can affect mortgage lenders who use residential as collateral. 10% of lenders most affected by flooding experienced losses about four times greater than the average lender.
Source: Bank of Canada — Flood Risk and Residential Lending
Extreme Weather and Insurance
A lender wants the property securing its mortgage adequately protected. Climate-related damage can therefore create another connection between environmental risk and mortgage lending.
The above noted Bank of Canada study found that only about 38% of homes with property insurance had additional flood insurance.
Extreme heat itself is obviously different from flooding. But the broader point is important: the physical environment surrounding a house can have financial consequences for the homeowner, the property’s value and ultimately the lender financing it.
The Bottom Line
None of this means that a heat wave is going to cause your house to lose value or your lender to change your mortgage.
The point is more subtle.
If extreme heat continues to become more common, people may increasingly think about how expensive a house is to cool. If buyers see financial value in those differences, then something a weather issue now becomes a mortgage issue.
