The declaration was made by the head of the National Disaster Management Center and announced by the government on Sunday. It allows the national government to co-ordinate the response to the disaster.
The worst impact is in the northern provinces of Limpopo and Mpumalanga, where the fatalities occurred. But the Ministry of Cooperative Governance and Traditional Affairs said at least three other provinces had also been affected by the severe weather.
Parts of South Africa and neighbouring Mozambique and Zimbabwe have experienced heavy rains for weeks. That resulted in severe flooding in central and southern Mozambique and northern South Africa. More than 100 people have died in the three countries since the rains began late last year.
The floods in northern South Africa caused the closure of the Kruger National Park and the evacuation of hundreds of tourists and staff members from flooded camps to other parts of the park.
The premier of Limpopo province said the weather had caused around $US240 million ($A357 million) in damage in her province, with many houses and buildings washed away completely.
More than 100 people died in floods last year in South Africa's Eastern Cape province in the south of the country, while more than 400 died in flooding in the eastern KwaZulu-Natal province in 2022.
South Africa's famed Kruger National Park was set to reopen for visitors after a suspension forced by heavy flooding which led to the evacuation of over 300 tourists and staff.
The park, which is one the biggest game reserves in the world covering about 2000 hectares bordering Mozambique and Zimbabwe, suffered extensive damages as heavy downpours devastated the Mpumalanga and Limpopo provinces and killed more than 20 people.
