Tucson, in the Sonoran Desert of southern Arizona, receives only around 300 mm (about 12 inches) of rain a year, split between gentler winter Pacific storm remnants and the more dramatic summer North American Monsoon from July through September. Monsoon storms here can build explosively over the surrounding mountain ranges in the afternoon, bringing intense lightning, dust storms, and flash flooding in the desert washes that define much of the region’s low-lying terrain. Because these storms can escalate from clear skies to severe within an hour, and because so much of the surrounding desert floods quickly when it does rain, radar tracking during monsoon season is a genuinely critical tool. NWS Doppler radar KEMX (Tucson) covers the region.
Learn more: How Does Rain Radar Work? · Open the full Rain Map