The Great Lakes are undergoing a trajectory of rapid warming coupled with a reduction in ice cover and an earlier onset of seasonal stratification. These changes could increase the probability of lake heat waves which threaten fisheries, tourism, and ecosystems. However, the interannual variations in the development of lake heat waves, which is important to better understand how they may change under future climate conditions, is not well understood. The Great Lakes have strong inter-seasonal connections in lake surface temperature, ice cover, and vertical thermal structure. For example, observations show a strong correlation between winter lake ice and consecutive summer lake heatwaves. In years with high ice cover, the maximum spatial extent of lake heatwaves is usually low, and vice versa. To understand how winter thermal and ice conditions impact summer stratification and heat extremes, we run a numerical experiment using our Great Lakes region climate model that we have newly developed in the last couple of years. This model resolves the atmosphere and land with 4-km and the lakes with 1-2 km in the horizontal. We compare two winters from the past 20 years, a cold winter with higher lake ice fraction and a warmer winter where the lake ice fraction is low. The model is run in a one-way coupling mode from the atmosphere to the lake to isolate the lake effects. We track the total heat content from winter to summer and quantify changes in lake surface temperature and vertical distribution of the total heat content. We use this to investigate how the ice-albedo feedback and ice insulation effect influence air-lake heat budget and affect the onset of summer stratification and heatwaves. Results will be presented at the conference.