The weather gets cold for a while and then it warms up again. We get a couple of big snowstorms and then it doesn’t snow much at all. Back, forth, up, down, weather is always changing from one side of average to the other. There is an ancient farmer’s proverb which goes, “There is no debt so surely met as wet to dry and dry to wet.”

However, a careful look at long-term weather records shows that weather is distinctly non-linear. Over long periods of time, the warm spells do not completely balance out the cool spells. Likewise, the wet periods do not balance out the droughts. The fact that we are on our second consecutive snowy winter does not mean we should expect less snow in the near future. In fact, weather averages are usually determined not by the period of record, but by the current three decades, owing to the fact that long-ago weather does not always make a relevant comparison.