There's a weird phenomenon that surrounds this difference between the two places. There's actually a German superstition that moving air causes illnesses, such as heart disease, pneumonia, and the flu. A lot of them open windows to air a room out, but they're afraid of opening windows on moving cars and trains - and there's not a lot of air conditioners in buildings. It's a weird thing my German teacher told us a while ago. Here's a couple articles on it. The weather in Washington, D.C., and Berlin, Germany, has been pretty similar recently. There is one striking difference between the two capitals, though: Whereas many Americans would probably never consider living or working in buildings without air conditioning, many Germans think that life without climate control is far superior.