Austin sits within the same “Flash Flood Alley” corridor as San Antonio, where the Balcones Escarpment forces warm, moisture-laden Gulf air upward and can trigger extraordinarily heavy rainfall over the region’s many creeks and the Colorado River running through downtown. The city averages around 870 mm (about 34 inches) of rain a year, but the real danger comes from a handful of extreme events, including catastrophic 2013 and 2015 floods that caught residents and even experienced hikers along local waterways by surprise. Because water levels here can rise from ankle-deep to dangerous in well under an hour, radar tracking of approaching storm cells is treated as a critical, routinely used safety tool. NWS Doppler radar KEWX (Austin/San Antonio) covers the region.
Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map