Global Climate Change and Illinois

Abstract

The climate of Illinois is greatly affected by the state's position in the middle of the North American continent, the third largest land mass on earth. The mountains in the western part of the continent are a formidable barrier to the prevailing westerly winds that circle the globe. But flat lands in the central United States permit air movement across the Midwest from both the frozen lakes of northern Canada and the warm Gulf of Mexico. The shape, size, and surface topography of North America set the stage for Illinois' climate.