Urban heat island effect in Canada: Insights from five major cities

Résumé

Climate change poses a significant global challenge, impacting regions differently. This study quantifies the spatiotemporal
patterns of diurnal, monthly, seasonal, and annual average urban heat island (UHI) intensity in Canada, a northern country, using data from five major cities: Toronto, Montreal, Vancouver, Edmonton, and Calgary, based on land surface temperature and land use data. Results indicate that each city exhibits distinct variations in UHI intensity influenced by its location, land use, and climate. In summer, Vancouver has the highest daytime UHI intensity at 7.25°C, while Toronto has the highest nighttime intensity at 4.36°C. In winter, Toronto has the highest daytime UHI intensity at 4.50°C, while Calgary has the highest nighttime intensity at 2.89°C. Edmonton records the lowest winter daytime UHI intensity at -1.29°C, with a nighttime increase reaching 2.86°C, due to the colder surrounding rural areas. Based on the spatial distribution, we found that high UHI intensity areas correlate with dense built-up areas, indicating that increasing urbanization intensifies the UHI effect. We also found that large water bodies have a cooling impact in urban areas during the day. This research can guide sustainable urban planning and policies tailored to local conditions, particularly in cities in Northern countries.