Just like at the end of the 2024/25 summer rainfall season, there is again a possibility that heavier rain could occur over this region until as late as May this year.
By Alani Janeke, senior journalist at African Farming and Landbouweekblad
Rain is possible over especially the central to eastern parts of the country during the first two weeks of April, says Johan van den Berg, an independent agricultural meteorologist. During the first week of April, rain is also possible over the central to northern half of the Northern Cape.
Van den Berg cautions that the moist conditions currently affecting especially the northern summer rainfall region could create challenging conditions for making lucerne hay and other crops.
“It is also negative in terms of pests and disease pressure, with quite a lot of standing water. Livestock farmers are already struggling with diseases, particularly in small stock, due to a build-up of parasites. However, the rain remains very welcome for many summer grain crops, especially late plantings, which will still benefit from it.”
Also read: Summer rainfall region – favourable chances for rain; winter rainfall region – extreme heat forecast
La Niña conditions continue
The rainfall conditions over the summer rainfall region are linked to the La Niña phenomenon, which is still influencing rainfall patterns, although it is weakening, Van den Berg says.
One of the most important indicators, the Southern Oscillation Index (SOI), remains in La Niña territory. On Monday 23 March, the 30-day running index still stood at a value of 12,31 on a scale from -30 (indicating a strong El Niño event) to +30 (indicating a strong La Niña event).
“Only at index values of around five (positive or negative) are conditions generally regarded as more neutral,” he says. “The current index values are still fairly strongly La Niña-leaning. Sea surface temperatures, however, are very close to the neutral threshold.”
Van den Berg explains that a positive SOI value at this time of year indicates a strong possibility of further rainfall in April and May. “It therefore appears that the current La Niña event could persist for about two months or longer than initially forecast.
“In a very similar year to this one, the 2024/25 summer season, very heavy rainfall continued into May, with widespread flooding. Although it is difficult to predict, there is a possibility of fairly heavy rainfall still occurring over the summer rainfall region before winter.”
Also read:
High risk of above-average and below-normal rain in the coming months – weather service
El Niño: Strong indications of below-average rainfall
