Edlund, an art director at CNNmoney, has a talent for imaginative data viz techniques (check out his take on the 2010 stock market, which renders the market's movements in song). The Weather Wheel, like all really clever infographics, is a pretty simple concept. But by organizing all of the data with maximum intelligence, you get a single, simple chart that manages to pack in far more information that you ordinarily see in such a small space.
First off, cities are ordered from left to right by average year-round temperature, with the hottest on the left. Second, the little ring below each city gives you an idea of what the temperature is in a given month -- and the months scroll past, like a wheel. Third, the little blue dot inside the circles tells you how much precipitation the city gets in that month. And finally, there are little arrows that fly past each city, giving you a sense for their windiness relative to all the others. (Thus, windier cities have arrows that fly by faster.)
Our only quibble is really with the size and legibility of the chart -- it would be nice if, for example, the circles were both larger and color coded to give you a clearer sense of monthly temperatures. But the real innovation here is the wheel, which allows you to see easily and intuitively how the data is flowing over time.
Granted, we have no idea how a visualization like this would be used -- but the technique is fascinating, and we're hoping to see more of it.