Weather service predicts below-normal rainfall for parts of Western Cape this winter

Recent heavy rains caused flooding in Nyanga, Cape Town. (Photo: Brenton Geach)

28 Mar 2025

After two good rainfall seasons with no major water storage stressors, the South African Weather Service has cautioned that the Western Cape is now facing a high likelihood of below-normal rainfall for its winter season — the period in which this region typically receives the majority of its rain.

For this coming autumn and winter, the most likely outcome from the predictions issued by the South African Weather Service (Saws) is below-normal rainfall across the Western Cape.

This was when the region typically received the bulk of its rainfall, Saws said during a media briefing with the Government Communications and Information System (GCIS) at Parliament on Thursday, 27 March 2025, and could mean further stress on water storage this winter period.

Saws lead scientist of long range predictions, Dr Christien Engelbrecht, said that the current seasonal forecast extended only up to mid-winter (with the forecast updated monthly).

Engelbrecht further said that low probabilities of above-normal rainfall were predicted over large parts of the summer rainfall areas during April, May and June 2025. She added that enhanced probabilities for above-normal rainfall were predicted over the far eastern parts of the country during mid winter.

This prediction of below-normal winter rainfall for the Western Cape comes after two good rainfall seasons, with no water storage stressors, according to Engelbrecht.

In fact, in 2024, the province had extremely good rainfall, with July recording one of the highest historical records of rainfall for that month. This was brought on by an onslaught of cold fronts that caused flooding, burst river banks, caused infrastructure damage and displaced people across parts of the province.

Saws executive on infrastructure and information systems, Mnikeli Ndabambi, said tens of thousands of people, as well as property and infrastructure, had been affected.

“Many shelters had their roofs blown away by the forceful winds. Moreover, residents waded through flood water inside their shelters. Furniture and other goods were damaged,” said Ndabambi.

Read more: July rainfall breaks records in Cape Town with more extreme weather to come

Hoping to better prepare Western Cape residents for the coming winter season and to improve public preparedness and response to severe weather conditions, Saws and the GCIS are undertaking to collaborate more with disaster management authorities, media, and NGOs.

The media briefing at Parliament by Saws and the GCIS is part of a new strategy, which they said would take place more often to better inform communities and mitigate the impacts seen in previous years.

Engelbrecht said that if their prediction for the 2025 winter materialised, the replenishment of the water storage would not take place as it should. This would then add pressure on to the next season, and could become a problem if the next season should also have below-normal rainfall.

The real problem comes in when there are multiple or consecutive seasons of below-normal rainfall during the main rainfall period for the particular region — in this case, the Western Cape.

western cape storm Flooded homes on 25 September 2023 in Sandvlei, Western Cape. (Photo: Brenton Geach / Gallo Images)

record rain western cape Flooding in Nyanga, Cape Town. (Photo: Brenton Geach)

Engelbrech said it was always a concern if there is a season of below-normal rainfall, but especially so if there were consecutive seasons of below-normal rainfall. This is why it was crucial that people in the province be proactive when it came to conserving water.

“If the prediction is for below-normal rainful, as it is currently, I think then one must use that as a guidance in planning to be proactive. We have no idea what the winter rainfall season of 2026 is going to be at the moment… If it’s an above-normal rainfall season, then it’s okay, but if it’s another below-normal rainfall… then one could again have real water stressors,” said Engelbrecht.

She said the good rainfall of the previous winter season had resulted in good vegetation activity, which was relevant now in the autumn (April to June) and midwinter (June to August) months.

The predictions were for below-normal rainfall in the Western Cape, but Engelbrecht said the current models predicted that this would be more so for the eastern-parts of the Western Cape — where above-normal maximum temperatures this winter and above-normal vegetation activity are predicted.

This means that there is an increased risk of veld fires in the eastern parts of the province, compared with the previous 2025 winter season. Engelbrect said that this is one of the risks for the upcoming winter period in the Western Cape.

A water-scarce region

Western Cape is a water-scarce region with its annual rainfall decreasing over the past few years. It is projected that rainfall in the Western Cape is likely to decrease by 30% by 2050.

This is being further affected by climate change, which the Western Cape government projected could lead to:

Decreased average rainfall.

A change in seasonality, location and intensity of rainfall.

Increased temperatures.

Increased wind speeds.

Increased wildfires.

“Water security is affected by climate change in three general ways: changes in annual rainfall, increased runoff that affects quality of water in streams and rivers, and increases in sea level,” said the Western Cape government.

It added that climate change increased pressure on water resources through increased temperature and associated evaporation, which was likely to be accelerated by high wind speeds and the related increase in frequency of extreme weather events.

Engelbrecht said the El Niño-Southern Oscillation was currently in a neutral state.

Read more: Has the La Niña weather pattern faded, and if not how long will it last?

Weather patterns in the Western Cape

The province has been experiencing more frequent and severe weather events, including flooding, increased wind speeds, increased temperatures, fewer cold frost days, and more fires.

The Western Cape government said that these altered climatic conditions impacted water infrastructure by disenabling effective infiltration to recharge groundwater, damaging infrastructure, increasing evaporation, and reducing the quality of water resources.

Ndabambi urged the public to timeously check the Saws website and social media channels for accurate weather advisories before travelling or making any plans — especially with Saws now issuing impact-based warnings for the public to better understand the impact of incoming weather.

This was particularly important as many parts of the province, including Cape Town, the Cape Winelands, Overberg, West Coast and Stellenbosch, often experienced severe cold fronts that brought about heavy rainfall, severe floods and gale-force winds.

Ndabambi said that driving these were three main weather systems the province experienced throughout the year:

Cold fronts, which tended to occur in autumn, winter and spring.

Cut-off low pressure systems, which tended to occur in early autumn, winter and spring.

Strong south-easterly circulation, which tended to occur only during the summer season.

The weather service cautioned that staying updated on weather advisories was a matter of life and death as the impacts of these events often resulted in damage to property and infrastructure, as well as the displacement of people and a threat to life.

Ndabambi said that cut-off low and cold front systems provided the majority of rainfall for the Western Cape.

Ndabambi said that as the winter season approached in June, Cape Town would start to experience more cold fronts. And climatologically speaking, Engelbrecht said April was the month that brought the highest frequency of cut-off lows.

“There can still be weather that results in high-impact weather events, even though for the season, on average, below-normal rainfall is predicted,” she said. DM

https://www.youtube.com/watch?v=REeWvTRUpMk

Categories:

Tags:

DM is much better if you are signed in...

South Africa

A water-scarce region

Weather patterns in the Western Cape