Temporal March of the Chicago Heat Island

Abstract

Twenty years of records from Midway Airport, located within the City of Chicago, and Argonne National Laboratory, a rural site 23 km southwest of the airport, have been used to study the diurnal and seasonal variation in the Chicago urban heat island. As expected, there was an elevation in temperature within the city most of the time, averaging 1.85°C during nonprecipitating hours. The magnitude of the heat island was characterized by diurnal and seasonal cycles, which were modulated by cloud and wind conditions. The influence of Lake Michigan on the magnitude of the heat island and on the location of its center is discussed, based on measurements at downtown and residential sites adjacent to the lake.