Sudestada (Southeast blow) is the Spanish name for a climatic phenomenon common to the Río de la Plata (an estuary formed by the combination of the Uruguay River and the Paraná River on the southeastern coastline of South America) and its surrounding region. The phenomenon consists of a sudden rotation of cold southern winds to the south-east. This change, while moderating the cold temperatures, loads the air masses with oceanic humidity, bringing heavy rain and rough seas in the coastal regions. The air circulation also increases the intensity of the winds. The Sudestada is most likely to happen between July and October.