Once again, South Africa is bracing for a powerful and disruptive weather system this week, as a cut-off low pressure system moves across the country, triggering heavy rainfall, plummeting temperatures, snowfalls, and the risk of flash floods.
According to the South African Weather Service (Saws), the weather system is set to make landfall over the western interior on Wednesday, April 23, and gradually track eastward until Saturday, April 26, 2025.
As it moves, widespread showers and thunderstorms are expected to impact much of the central and eastern regions, with some areas experiencing over 50mm of rain in just 24 hours.
“Many areas are already waterlogged and flooded, and with more rain expected the risk of flash flooding remains high,” warned Michelle du Plessis, meteorologist at Vox Weather.
Gauteng metros on high Alert
Just over a month after a devastating storm hit Pretoria in February — and shortly after wildfires raged in Cape Town — the City of Tshwane and City of Johannesburg metros are once again on high alert.
This comes as the South African Weather Service (Saws) issues a Yellow Level 3 warning for severe thunderstorms expected over parts of Gauteng.
Emergency services departments in both cities are on standby, monitoring developments closely.
According to Saws, there is a 60%–80% chance of rain in Tshwane, and severe thunderstorms are expected from 11am until midnight on Wednesday. The storms could bring intense downpours, hail, strong winds and localised flooding.
What is a cut-Off low?
Cut-off lows are potent weather systems that often form during seasonal transitions like autumn or spring.
Characterised by upper air troughs that disconnect from the main flow and operate independently, every year in South Africa, COL pressure systems severe weather conditions and heavy rainfall, often leading to flooding, devastation and destruction of economic activities
High-risk areas
The Free State and North West provinces are especially vulnerable, with forecasts predicting severe thunderstorms, hail, and flooding. Saws has issued a Yellow Level 4 warning for disruptive rainfall over large parts of the country.
“Flooding of roads and settlements, and damage to infrastructure, vehicles, and livestock are possible,” Saws warned.
Heavy rainfall will persist along the east coast – especially in KwaZulu-Natal and the Wild Coast – until Saturday, while parts of the Gauteng, Highveld, and Bushveld regions will also receive significant rainfall.
Snowfall in the Drakensberg
Temperatures are expected to drop sharply midweek, resulting in snowfall across the Drakensberg mountains in Lesotho, KwaZulu-Natal, and the Eastern Cape.
“Freezing levels have dropped significantly,” Vox Weather reported, with up to 15cm of snow expected in central and eastern Lesotho, and more than 20cm around Afriski.
Lehlohonolo Thobela, Saws forecaster, explained, “That’s why you will start seeing snow over the high-lying areas of the Drakensberg mountains into KwaZulu-Natal, as well as the extreme eastern parts of the Eastern Cape into Lesotho.”
Climate factors and change
While cut-off lows are a regular part of South Africa’s autumn weather patterns, meteorologists are noting an unusually wet season.
“This year has been unusually wet across many parts of South Africa,” Du Plessis noted, citing the influence of a weaker La Niña phase.
Though the El Niño-Southern Oscillation (ENSO) is currently neutral, local systems and tropical influences are playing a stronger role in recent weather events.
Professor Guy Midgley of Stellenbosch University’s School for Climate Studies stressed that “every aspect of weather is altered in some way” by climate change. “The atmosphere and oceans are now much warmer than even 10 years ago,” he said.
“We need to learn from these extreme events very fast if we are to adapt to these changes,” Midgley added.
Safety measures
Saws is urging the public to:
- Avoid flooded roads and low-lying areas.
- Stay indoors during heavy rain or thunderstorms.
- Move valuables, vehicles, and livestock to higher ground.
- Secure outdoor items and monitor weather updates.
Emergency services remain on standby, and residents are advised to download the WeatherSmart App or follow Saws on social media (@SAWeatherServic on X and @WeatherServic on Facebook) for real-time alerts.
As storms gather across the country, South Africans are urged to stay vigilant and prioritise safety.
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