What Are Consistent Weather Patterns Over Long Periods of Time?

Consistent, prevalent weather patterns over long periods of time are known by the term "climate." Weather is the state of the atmosphere's moisture, humidity, sunshine, cloudiness, temperature, fog, frost, hail and wind speed at any moment. Climate is a statistical average of these factors over long periods, usually 30 years.

Climate is more predictable than weather, which can change in a matter of minutes or even seconds if it suddenly begins raining, is suddenly cloudy or the temperature drops with a wind gust. Climate can be predicted more consistently than weather because it is defined by long-term averages. For example, it can be expected to snow in winter and rain in spring in the northern latitudes of the United States. Similarly, in New Mexico and Arizona, summer rains come during what is known as the monsoon season.

While climate gives some predictive ability to meteorologists, weather conditions vary widely in any region and season. For example, the extremely hot summer of 2011 in the United States did not necessarily mean subsequent summers were hotter than normal. In fact, in July 2014, many places from the Great Lakes to the Deep South saw the coolest temperatures on record. The climate was consistent with previous decades, however, in that these areas were many degrees warmer on average than they had been in the winter seasons.