How Sunshine Shapes Cities' Population Growth, in One Chart

If you're like me, you spend the week of July Fourth finding excuses to get outside in the sun, and reading policy papers on urban growth in the 20th century. Fortunately those two things aren't as unrelated as they might seem. In fact, as we're reminded by a recent review of the causes of city population changes, few variables have predicted metro area growth in the past century as well as warm weather.

It's easy to overlook weather as a legitimate living factor, if only because the idea of moving somewhere just for the sunshine feels a bit too simplistic. And for sure, the reasons why certain cities grew faster than others in the 20th century are as numerous as they are complex. But when urban scholars have studied population changes during this period, they've routinely found a pleasant climate to be a powerful draw.