In May 2026, successive low-pressure systems brought destructive flooding, landslides and damaging winds to large parts of South Africa, and caused fatalities, widespread damage to buildings and major infrastructure disruption across long stretches of coastline and interior provinces.
According to an article by JBA Risk Management, rainfall totals exceeded 300mm in some areas, inundating communities, isolating towns and disrupting businesses. At the same time, transport, electricity and agricultural sectors experienced what the article called “significant disruption”.
“The event is particularly notable due to the scale and persistence of the flooding, the exposure of vulnerable communities and critical infrastructure, and the growing financial pressures associated with South Africa’s widening flood protection gap,” said the article.
Factors leading to the event
The floods were triggered by a succession of intense low-pressure systems affecting the southern and interior regions of the country, JBA Risk Management stated.
“While such systems are not uncommon during the austral autumn, the severity of this event was exceptional due to the rapid intensification of the systems, their slow movement and the persistence of high rainfall totals over already saturated catchments.”
The first major system developed rapidly between 5 and 6 May 2026 across the Eastern Cape.
“Its formation was driven by a cut-off low in the mid- to upper-troposphere, which enabled a plume of warm, moist air from the Indian Ocean to move southwards across southern Africa,” the article noted.
“This interaction deepened the surface low-pressure system and generated widespread convective activity, resulting in severe thunderstorms with heavy rainfall.”
The article also said: “At the same time, a ridge of high pressure strengthened over Namibia and parts of the Northern Cape. The strong pressure gradient between the two systems generated damaging winds, with gusts exceeding 97km/h in exposed areas and mountainous terrain.”
The second significant series of low-pressure systems affected the country from 10 May.
According to JBA Risk Management, “these systems were associated with intense cold fronts and heavy downpours, approaching from the west from over the South Atlantic Ocean”.
Driven by an intensification and amplified loop in the Southern Hemisphere polar jet stream, the cold fronts brought further persistent heavy rainfall to the Western and Northern Cape.
Between 6 and 12 May, mountainous regions of the Western Cape received up to an estimated 600mm of rainfall, exacerbating flooding impacts in areas already affected by the earlier storm systems.
The impact of the floods
On top of fatalities, “the floods caused widespread disruption and damage across South Africa, affecting at least six provinces”.
Across the Garden Route District and other parts of the Western Cape, JBA Risk Management noted that the storms caused major damage to transport and utility infrastructure, and also led to forced evacuations.
The second storm system, which struck from 10 May onwards, brought further fatalities and displacement, JBA Risk Management added. This event also brought gale force winds.
As the Breede River in the Western Cape’s Winelands district burst its banks, multiple vineyards also experienced flooding.
“For one producer, 15 hectares of new vineyards planted last year, and 1.3m bottles of stock were inundated in up to 2m of flood water,” the article said.
“The floods will certainly have financial impacts on the Western Cape wine industry, which contributes ZAR50.9bn ($3.1bn) to the national GDP and supports 245,000 jobs.”
JBA Risk Management also highlighted that the event “demonstrated the vulnerability of both urban and rural communities to extreme rainfall and highlighted the cascading impacts of severe flooding on infrastructure, transport and the agricultural sector across southern South Africa”.
Insured losses
“Based on economic losses from recent historic flood events, the May 2026 floods are likely to be a multi-million US-dollar loss event,” said the article.
“The storms made landfall in quick succession and impacted parts of the country. The losses are likely to be driven by public infrastructure damage, residential property losses, business interruption and emergency response costs.”
Insured losses are also expected to be lower than total economic losses, and reflect South Africa’s estimated 71% Nat CAT protection gap.
“Flood insurance penetration remains particularly low in rural communities and informal settlements where the May 2026 floods caused the most severe impacts,” the article said.
“As a result, much of the losses will likely fall on households, businesses and the national government rather than (re)insurers.”
An exceptional event
Although JBA Risk Management considers the May 2026 South Africa floods to be an exceptional event “due to the rapid intensification of multiple low-pressure systems and high rainfall totals over saturated catchments”, it also noted that the floods highlighted the growing financial and humanitarian impacts of severe flooding across the region, particularly in areas of low insurance penetration and high property and infrastructure exposure and vulnerability.
“The event reinforces the importance of supporting underwriting, portfolio management, climate stress testing and disaster resilience planning in preparing for severe flood events,” said the article.
The 22nd Asia Nat CAT and Climate Change Conference is being held in Manila, Philippines, from 25 to 26 June 2026, and JBA Risk Management is a sponsor of the event.