The term “normal” once referred to the statistical idea of average (the norm), but in recent decades the word has acquired instead the medical connotation of “healthy.” Even the hard sciences are affected. In good science, the opposite of normal (abnormal) in the statistical sense means “not average”; that is, above average or below average. No judgement is implied. However, when one switches to the frame of reference acquired from medicine, the opposite of normal is “pathological,” and a value judgement is very definitely evident. This switch or drift in the meaning of normal has become practically universal and increasingly harmful.
Weather is just one of many areas where we have lost sight of what constitutes normal. We now use a medical model rather than a statistical one. (photo credit: wpclipart.com)