Cape Town - After the extreme heat and humidity experienced in the Western Cape this summer, the South African Weather Service (SAWS) said people should be prepared for hotter days as February approached, the hottest month on average for South Africa.
UCT Climate System Analysis Group (CSAG) deputy director Christopher Jack said the recently experienced heatwave was the kind of extreme weather that could be expected to be experienced more frequently.
Jack said these conditions would continue for the next several decades and even longer if global efforts to reduce emissions failed, proving that these conditions were indeed a symptom of climate change.
In agreement, Department of Water and Sanitation (DWS) spokesperson Sputnik Ratau said the recent floods in some provinces and the heatwave in the Western Cape this past weekend was proof that climate change was not some distant phenomenon but was happening right now.
The Cape Town Weather Office said: “This past weekend's weather was a typical summer circulation and since we are approaching February which is the hottest month on average for South Africa, there is a possibility that the Western Cape can experience hotter days, even though the seasonal outlook is indicating normal to below-normal maximum temperatures for most of the country.”
“South Africa is warming up, but there can be cooler years in the future,” said the weather office.
Jack said the evidence was clear that Cape Town had warmed around 1ºC relative to pre-industrial times (end of the 19th century), and was currently warming at more than 0.1ºC per decade.
“While this may not seem enough of an increase to even notice, where we really do notice it is in the frequency and intensity of extreme high temperatures like we experienced last week,” said Jack.
The weather office said even though the temperatures were expected to get warmer due to climate change, it did not mean that cooler-than-normal day and night temperatures wouldn’t be experienced in the future, since this could be caused by stronger synoptic weather systems - such as cold fronts or cut-off lows that would still influence the weather of the Western Cape.
Essentially, what this meant was that even though cooler than usual temperatures may be experienced at times, South Africa is still warming up.
Jack said most of the summer has actually been slightly cooler than normal, which was the kind of natural variation that should be expected now and in future.
The CSAG deputy director said insight into the recent humidity was more complex and required further analysis of the system that produced the heat wave.
However, Jack explained that in general, very high temperatures in Cape Town were the result of “air advecting off the higher inland areas”.
“High humidity is the driver behind higher temperatures feeling even higher. High humidity reduces the efficiency of the human body’s cooling mechanisms and so a hot humid day feels more uncomfortable than a hot dry day,” said Jack.