A Climatological Study of the Urban Temperature Anomaly in the Lakeshore Environment at Toronto

Abstract

Metropolitan Toronto (population of about 2,160,000 and area of 2282 km²) is on the north shore of Lake Ontario (area of 19,400 km²). The interaction between the daytime urban heat island and the lake circulation is studied using several years of records of daily maximum temperatures from a network of about 23 observing stations, pre-stratifying the data according to the regional wind patterns at the geostrophic level and according to the daily sunshine total. The results show that the heat island exists and is detectable during the time of maximum heating in Toronto. Further, the position of the heat island, although a result of urban influence (automobile traffic, industry, home heating units, etc.), is displaced in response to regional and lake breeze wind patterns and the modification of the lake breeze as it moves across the built-up area.