Detailed Time Variations in Mean Temperature and Heat Content of Some Madison Lakes

Detailed variations in the mean temperature and heat content were studied for 5 years in Lake Mendota and 3 years in Lakes Monona and Waubesa near Madison, Wisconsin. The data show that the heat content may vary significantly within 2 or 3 days and that the specific time of maximum heat content is unpredictable. Accurate determinations of heat budgets require frequent sampling over long periods. A Birgean annual heat budget may not necessarily reflect the influence of a lake on the surrounding environment. Thermal discharges had little influence in determining the mean temperatures of Lake Monona.