Las Vegas sits in the Mojave Desert and receives only around 110 mm (about 4 inches) of rain a year, one of the driest major cities in the country, but the surrounding valley’s hard, sun-baked desert soil and extensive paved surfaces mean that even brief, infrequent summer monsoon thunderstorms can cause severe, fast-moving flash flooding, since there’s essentially nowhere for sudden rain to soak in. The city has built an extensive underground flood-channel system specifically to manage these rare but dangerous events, some of which have proven deadly for people caught in normally-dry washes. Because a typical week involves zero rain, radar becomes critical during the brief summer monsoon window. NWS Doppler radar KESX (Las Vegas) covers the region.
Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map