Scorching weather ahead: Warning issued about heatwave hitting South Africa

Hot temperatures will persist over the next two weeks, with heatwave temperatures expected to rise to 40°C in some parts of the country.

City of Tshwane Emergency Services Department Spokesperson Lindsay Zwelithini Mnguni has called on residents to take note of a heatwave advisory issued by the South African Weather Service (Saws), which includes temperatures of up to 38°C in Hammanskraal.

Zwelithini Mnguni said residents should take precautions against the adverse effects that may be caused by extended exposure to extreme hot weather conditions, including dehydration, heat exhaustion, and heat stroke.

Heatwave can soar until mid-December

Vox weather meteorologist Annette Botha said a heatwave was expected over parts of the North West, Gauteng, Mpumalanga, Limpopo, the Free State and KwaZulu-Natal, which may last until 14 December.

This week, some of the hottest temperatures include 43°C forecasts in Musina and Phalaborwa on Wednesday and Thursday, 42°C on Thursday in Skukuza, 41°C on Wednesday in Thabazimbi, Lephalale, and Bela-Bela, 39°C in Rustenburg, and 37°C in Pretoria.

“In between, one or two days may occur when temperatures drop below the heatwave threshold, but it will remain warm,” she said.

Botha said several heatwaves are expected over the next two weeks, but discussing each town individually is complicated.

“Therefore, we generalise and indicate that multiple heatwave conditions are possible over this period, with short breaks in between in certain locations,” she said.

Temperatures can surge 10°C above average

Botha explained that heatwave conditions occur when a particular town’s maximum temperature is 5°C or more above the average maximum temperature of the hottest month for that location.

“Pretoria’s average maximum temperature for the hottest month is 29°C, with the heatwave threshold at 34°C. In the next two weeks, temperatures could rise 2°C to 3°C higher than the heatwave threshold, meaning that Pretoria’s temperatures could rise into the high 30s.

“The same pattern applies to other areas where heatwave conditions are expected, with temperatures that could rise to 4 or 5°C above the heat wave threshold – up to 10°C warmer than the average temperature of the hottest month,” she explained.

2024 on track to break heat records

Botha said that according to the World Meteorological Organization (WMO), 2024 was on track to be the hottest year on record, as the global average temperature for January to September 2024 rose about 1.54°C above pre-industrial levels.

She added that the University of Pretoria’s seasonal forecast and the SA Weather Service’s seasonal climate watch suggest above-normal minimum and maximum temperatures can be expected nationwide.

“These higher temperatures are supported by the forecast of ENSO [El Niño–Southern Oscillation]-neutral conditions that may move towards a weak La Niña, which often leads to warmer temperatures. It is important to note that a weak La Niña does not necessarily bring the typical colder and wetter conditions usually associated with it.

“Instead, it could cause drier and warmer conditions in certain regions, including South Africa. Less cloud cover, increased solar radiation and the general warming trend of the earth play a role in the observation of higher temperatures, even during weak La Niña events,” she said.

Botha said climate change reinforces these patterns, increasing the likelihood of extreme temperatures regardless of the ENSO phase.

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