Cardiff sits in Wales, one of the wettest parts of the United Kingdom, where mountainous terrain wrings substantial rainfall out of Atlantic weather systems arriving from the southwest.
The Welsh capital sits where the Taff and Ely rivers meet the Severn Estuary, giving it one of the largest tidal ranges in the world alongside its rainfall risk. The combination of steep valleys and high rainfall totals makes parts of Wales prone to fast river rises, and radar tracking helps distinguish a passing shower from the kind of sustained rain that leads to river flooding. Learn more: Flash Flood Warning Signs on Radar · Open the full Rain Map