Look at a map and locate Seattle, Washington. Follow that latitude east to International Falls, Minnesota. These spots are at roughly the same latitude. Yet the average January temperature in Seattle is a relatively balmy 7? C (45? F) when compared to International Fall's -15? C (4? F). While traveling north, temperatures tend to go down. This is because sunlight travels through the atmosphere at a greater angle and less energy reaches the ground. But why are there such a huge discrepancy between two places at the same latitude? While the complete answer is more complicated, it can be partly explained through a class barefoot trip to the beach.