9 January 2024
Rainfall of less than 20 mm is possible roughly west of the N1 up to the Namibian border and north of the Orange River this week, with heavier rainfall predicted elsewhere.
“In the second half of January, rainfall conditions are weakening over almost the entire summer rainfall region, with the exception of the eastern parts, especially Mpumalanga, where rainfall of 20 mm or more may still occur,” says Johan van den Berg, an independent agricultural meteorologist.
There are indications that tropical low-pressure systems (not strong enough to be classified as cyclones) north of Madagascar in the Indian Ocean may intensify in the second half of January.
“This could cause drier conditions, especially over the central to western parts of the summer rainfall region. With less rain, it could be accompanied by very warm conditions,” says Van den Berg.
Winter rainfall region
In the winter rainfall region, very little to no rain is expected until at least the end of January. Very hot conditions are predicted in places such as Worcester, the Hex River Valley and Robertson, with temperatures of up to 40°C expected, especially from 12-20 January.
“Weather systems currently suggest that the trend of persistent extremely warm conditions in most of February will continue over large parts, especially the inland areas of the Western Cape. This could lead to very high water consumption, evaporative losses and even heat damage to fruits,” says Van den Berg.
December rainfall better than expected
Meanwhile, rainfall conditions in December were considerably better than expected. A cut-off low-pressure system developed over the western parts of South Africa in the last week of December. This brought heavy rain, especially to the western parts of Botswana, the eastern parts of the Northern Cape (with smaller patches of heavy rain more west and southwest, as in Calvinia, Pofadder, Williston and Garies), the southwestern parts of the Free State, parts of Lesotho and the northern parts of the Eastern Cape.
Good rainfall also occurred in large parts of Limpopo, Gauteng, KwaZulu-Natal and Mpumalanga. The heaviest rainfall in the last 10 days of December was recorded in Van Reenen (238 mm), Graskop (219 mm), Orania (160 mm), Tzaneen (149 mm), Coffee Bay (139 mm), Hanover (108 mm) and Upington (68 mm). Most of North West received much less rain.
Large parts of the lower Orange River region, as far west as Augrabies, received more than 40 mm of rain, causing significant problems and damage to grapes that are ready for harvest. Livestock farmers in the Northern Cape rejoice over the good rain but there are areas west and north of Upington that have still received almost none. The minimal rain in North West is also a cause for concern for summer grains.
“While reasonably large areas in the summer rainfall region did receive rain, there are still smaller parts in other provinces getting less rain, such as east of Gauteng in places like Delmas and Middelburg, which need regular rainfall in the next few weeks to prevent drought damage. It is also crucial that more rain, especially in February, occurs in other areas,” says Van den Berg.
