Severe Tropical Storm Domoina in 1984 caused 100-year floods in South Africa and record rainfall in Swaziland. The fourth named storm of the season, Domoina developed on January 16 off the northeast coast of Madagascar. With a ridge to the north, the storm tracked generally westward and later southwestward. On January 21, Domoina struck eastern Madagascar, the third storm in six weeks to affect the nation; collectively, the storms caused 42 deaths and $25 million in damage (1984 USD). After crossing the country, Domoina strengthened in the Mozambique Channel to peak 10-minute sustained winds of 95 km/h (60 mph). On January 28, the storm made landfall in southern Mozambique, and slowly weakened over land. Domoina crossed into Swaziland and later eastern South Africa before dissipating on February 2.

In Mozambique, Domoina dropped heavy rainfall in the capital Maputo that accounted for 40% of the annual total. Floods in the country destroyed over 50 small dams and left widespread crop damage just before the summer harvest. Later, the rains caused the worst flooding in over 20 years in Swaziland, which damaged or destroyed more than 100 bridges. Disrupted transport left areas isolated for several days. In South Africa, rainfall peaked at 950 mm (37 in), which flooded 29 river basins, notably the Pongola River which altered its course after the storm. Flooding caused the Pongolapoort Dam to reach 87% of its capacity; when waters were released to maintain the structural integrity, additional flooding occurred in Mozambique, forcing thousands to evacuate. Throughout the region, Domoina caused widespread flooding that damaged houses, roads, and crops, leaving about $199 million in damage. There were 242 deaths in southeastern Africa.