Of course, latitude and natural topology are important here, but the contemporary heat-retaining urban/suburban concrete slab landscape certainly isn’t helping. Put another way, passive solar technology is already in widespread use in urban “heat islands,” only in many places, it makes things worse rather than better. You can watch Atlanta help create thunderstorms.

I’ve been able to test the heat island effect out on an anecdotal basis by trying longer but more well-shaded routes to work, and I did notice some improvement (there’s no escaping the cruel, cruel humidity). Of course, that particular study is worth the paper it’s printed on, so it’s somewhat gratifying to see actual numbers on the effect of shade trees on temperature.