So all of this is fascinating for people who love rain, but why does the size of droplets matter? Well, it turns out that knowing the droplet size allows scientists to more accurately predict rainfall, which could especially help plan if area is at risk of flooding. And knowing droplet size could also help scientists better understand how a storm might weaken. That's because smaller droplets evaporate more quickly. That evaporation cools the air and creates downdrafts, which can dissipate the storm. During that next summer storm, instead of cursing the fact that you left your umbrella at home, marvel at the complexity of the water falling from the sky.