Photo: Flickr | Santosh Kumar
When almond trees shed leaves later than normal and some deciduous trees bloomed in February, Giel Hugo, a specialist weather forecaster based in the Overberg, Western Cape, knew it would be an unusual year.
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His observation turned out to be accurate when good early-season rainfall in late autumn to mid-winter gave way to sparse rainfall later in winter and spring.
By the time Nampo Cape rolled around in the second week of September, many Overberg wheat fields were marred by brown, dead patches, and some growers told Farmer’s Weekly they were putting off inspecting their barley plantings for fear of what they might find.
“For the Western Cape, the most important factor determining how many cold fronts we will get and how strong they will be is the polar vortex, which has the function of retaining cold air around the South Pole,” Hugo explained.
“Early 2025 saw increased ice formation around the South Pole, and the polar vortex was spinning quite powerfully, producing initial strong cold fronts that brought rain to the Western Cape, but these began to subside as the vortex weakened by August.”
Summer rainfall areas
Johan van den Berg, a Free State-based independent agricultural meteorologist, said that, in contrast, the periods from March to April and November to December received unusually high rainfall in the eastern parts of the country.
“Compared with the long-term average, cumulative rainfall over those four months in 2025 ranked among the top 5% on record. In some parts of the country, November saw the third- or fourth-highest rainfall ever recorded for the month.
“Thanks to these high figures, dam levels in the east of the country still look good for this time of year; in fact, for the past three years, dams have been unusually full for this early in summer.”
Hugo added that the cut-off low-pressure system that caused the Vaal Dam to overflow in April was unprecedented.
“You don’t expect to see these cut-off low-pressure systems north of 30° latitude in winter. The authorities came in for a lot of criticism for not anticipating the floods, but no weather forecaster would have been able to predict that system beforehand. It was an anomaly,” he explained.
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Moreover, Hugo said that cooler-than-usual sea temperatures off Nigeria and Tanzania led to high-pressure systems that blocked the flow of warm, moist air from the equator this spring, while the heavy rainfall in the north-eastern parts of the country instead originated over the Mozambique Channel.
This situation appears to be normalising, and he said there is a chance that the western parts of the summer rainfall areas could also receive limited rainfall later in the summer.
Van Den Berg added that there are concerns about dry conditions in parts of the summer rainfall regions.
“Parts of the southern Free State, the Northern Cape, and the Eastern Cape remain very dry. The Garden Route is also struggling; from July onwards, there was virtually no run-off water into those parts, as there was so little winter rainfall,” he said.
A drier outlook
Van den Berg said the short-term outlook for summer rainfall areas is that early summer will bring good rainfall, but this could taper off from the second half of January into February and March.
“The possibility of a midsummer drought is slightly stronger than usual because when the beginning of a season is as wet as we’ve seen, this often causes the dry period that follows to be longer and drier,” he explained.
Thanks to the rain, the quality of grazing is not yet a concern in most production areas.
For the winter rainfall areas, Van Den Berg and Hugo agree that the Western Cape is probably entering a drier cycle.
“Looking at the statistics for the Western Cape, the period between 2012 and 2016 was relatively wet, but from 2017 onwards, it became drier. A wetter period then followed from 2019 to 2024. Now, in 2025, weather patterns are beginning to resemble those of 2017,” Hugo said.
“In addition, climate models indicate that these areas can expect drier conditions.”
Hugo also pointed to a third indicator, the level of solar activity, which suggests conditions may become drier.
“Solar activity has already peaked and is now on a downward slope. Historically, periods of lesser solar activity have coincided with drier-than-normal conditions,” he explained.
He added that a clearer picture of the winter rainfall outlook will emerge between January and March, when the strength, frequency, and orientation of cold fronts from the polar vortex will indicate the winter ahead.
“If the fronts are oriented from east to west, the winter is likely to be dry, but if they are oriented from north to south, the chances are better that the Western Cape will get strong cold fronts and good rain in winter,” he said.
Weak La Niña state points to wetter summer in North-East SA
In a media statement issued on 18 December to accompany its Seasonal Climate Watch for December 2025 to April 2026, the South African Weather Service (SAWS) said weather systems were transitioning “towards a weak La Niña state”, which “typically brings above-normal summer rainfall to the north-eastern parts of South Africa, including Gauteng, Limpopo, Mpumalanga, KwaZulu-Natal, parts of North West, and the Free State”.
“Climate model predictions suggest an increased likelihood of above-normal rainfall over the central and eastern parts of South Africa, particularly in the north-eastern summer rainfall regions. These wetter-than-usual conditions are consistent with the typical impacts of La Niña episodes and are expected to persist into mid-to-late summer.
“Regarding temperatures, minimum temperatures are forecast to be above-normal across most of the country, while daytime maximum temperatures are likely to be below-normal in the north-eastern regions as a result of increased cloud cover and rainfall. Above-normal maximum temperatures are, however, expected over parts of the south-western regions,” the SAWS added.
