Hermosillo sits in Mexico’s arid northern desert region, where a dry climate keeps annual rainfall low, but the North American Monsoon brings a short but intense rainy season from July through September.
In Sonora’s desert region, the city’s summer monsoon thunderstorms are the main source of flash flooding in an otherwise very dry climate. Because the desert landscape sheds water quickly rather than absorbing it, monsoon thunderstorms can produce flash flooding well out of proportion to the region’s usual dryness, and Mexico’s Servicio Meteorologico Nacional radar network is a key tool for tracking these fast-developing storms. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map