The question whether to walk slowly or to run when it starts raining in order to stay as dry as possible has been considered for many years—and with different results, depending on the assumptions made and the mathematical descriptions for the situation.
BBC reports that Franco Bocci, publishing in the European Journal of Physics, now asserts that both wind direction and a person’s stature figure into the answer:
In most cases, the general answer is to run as fast as possible; but the answer changes in a tailwind, or for the thin.
As for wind direction – and again, in general – you should run as fast as you can unless the wind is behind you, in which case the optimal speed will be exactly the speed of the wind.
In summary, if you want to stay the most dry in the rain: it’s better to run fast. Unless you’re thin. And there’s wind.