According to the NOAA (National Oceanic and Atmospheric Administration) Nevada is the driest state in the nation in terms of annual average precipitation (combined rain and snowfall). Las Vegas and Reno rely on water supplies that come primarily from mountains outside of Nevada. Temperatures have risen by 2.4 degrees (F) since the beginning of the 20th Century. The entire region.
The drought that has enveloped southwestern North America for the past 22 years is the region’s driest megadrought—defined as a drought lasting two decades or longer — since at least the year 800, according to a new study in the journal Nature Climate Change.