Making the decision to close schools for bad weather, as many regions in the US did last Tuesday due to the bitterly cold freeze, is not easy. The prime considerations of course are the temperature and snow and ice levels. As to the first, it is not the predicted daytime high temperature that should be used as a gauge, since that is usually reached only by the mid afternoon when students and workers are returning home in daylight and people have had time to do some clean up, but the low temperatures of the previous night, since that is closer to the temperature in the early morning when children are headed off to school. Last Tuesday, that temperature in Cleveland was -8oF (–22oC), which is pretty cold. [Read more…]