Great Lakes school administrators are among those who hold out the longest before closing schools for snow, according to this map of how many inches trigger such an action. Any snow – in fact, any prediction of snow – triggers closings in the south, according to mapmaker Alexandr Trubetskoy, who recently posted the map to Reddit. That doesn’t necessarily mean administrators in the south are wimps. Areas without much snow also don’t have much snow removal equipment. Trubetskoy identified himself as a high school student from Vienna, Va., in a Reddit message to Great Lakes Echo.