Great Plains - Climate

Climate

In general, the Great Plains have a wide variety of weather through the year, with very cold and harsh winters and very hot and humid summers. Wind speeds are often very high. The prairies support an abundant wildlife in undisturbed settings. Humans have converted much of the prairies for agricultural purposes or to create pastures. The Great Plains have dust storms mostly every year or so.

The 100th meridian roughly corresponds with the line that divides the Great Plains into an area that receive 20 inches (510 millimetres) or more of rainfall per year and an area that receives less than 20 in (510 mm). In this context, the High Plains, as well as Southern Alberta, south-western Saskatchewan and Eastern Montana are mainly semi hot steppe land and are generally characterised by rangeland or marginal farmland. The region (especially the High Plains) is periodically subjected to extended periods of drought; high winds in the region may then generate devastating dust storms. The eastern Great Plains near the eastern boundary falls in the humid subtropical climate zone in the southern areas, and the northern and central areas fall in the humid continental climate.

Many thunderstorms occur in the plains in the spring through summer. The southeastern portion of the Great Plains is the most tornado active area in the world and is sometimes referred to as Tornado Alley.