Cooling the Urban Heat Island

Urban communities are often hotter in the summer than rural areas. This phenomenon is called urban heat island effect and it’s expected to get worse with climate change.

Urban heat island effect is felt most in neighbourhoods with fewer trees and green spaces. Hard surfaces like rooftops, roads and parking lots absorb and radiate heat. Buildings and houses that are close together reduce air movement and trap heat, increasing local air temperatures and decreasing air quality.

Planting more trees in our neighbourhoods is an important way to reduce urban heat and prevent heat-related illness. Trees absorb heat, provide cooling shade, and cool the surrounding air. You experience the cooling power of trees when you seek relief from the hot sun in the shade they provide.

Communities with large, mature shade trees can be up to 11 degrees cooler than those without. A recent study has projected that if the City of Brampton increased tree cover in one of its most heat-vulnerable areas from 18 per cent to 33 per cent (about 54,000 trees), it would reduce the average temperature by 1.5 degrees, have fewer extreme heat days and save millions in energy and health care costs.

Scientists predict we’re going to experience more frequent extreme heat days above 30 degrees Celsius. You can help keep your home and community cooler by planting trees in your yard. Find the tree that is right for you in our Woodland Plants for Landscaping guide

Canada’s Climate Atlas

How will climate change affect your community? Explore Canada’s Climate Atlas to see how climate change will affect rain, weather and temperature patterns in your community and across the country.

Learn more about how climate change will affect our cities and what we can do to build climate-resilient neighbourhoods. 

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