South Africa’s winter turned harsh this week as snow, wind chill and icy temperatures swept across the country.
As temperatures plunged around the country, the situation has been worsened by strong winds which caused the real temperature to drop even further.
Vox weather meteorologist Michelle du Plessis said wind chill refers to the perceived decrease in air temperature the human body feels due to the flow of wind.
Wind chill
“When wind blows across exposed skin, it increases the rate of heat loss from the body, making it feel colder than the actual air temperature,” she said.
“This is because moving air strips away the thin layer of warm air that insulates the skin.”
Du Plessis said the wind chill index is calculated using a formula developed by the National Weather Service in the US, which considers air temperature and wind speed.
“For example, at 5°C with no wind, it feels like 5°C. At 5°C with a wind of 30km/h, it feels closer to 0°C,” she said.
Du Plessis said the UK was generally colder than SA. “The UK has a temperate maritime climate under the Köppen climate classification with cold, wet and cloudy winters with an average of temperatures – southern England: 0°C to 7°C; northern Scotland: often below 0°C.”
Du Plessis said frost, sleet and snow were also more common.
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South Africa’s diverse climate
“South Africa has a very diverse climate. The Cape is wet in winter, but Free State, Gauteng, North West, Limpopo and Mpumalanga are dry in winter.”
Du Plessis said average temperatures also vary across the country.
But if comparing the coldest places in SA with the coldest places in the UK, she said, the coldest place in the UK was Altnaharra, Scotland in the Scottish Highlands with a record-low temperature of -27.2°C recorded at Altnaharra on 30 December, 1995 and a typical winter low of -5°C to -10°C.
In South Africa, the coldest place was Buffelsfontein (Molteno area) in the Eastern Cape, near the Sneeuberg Mountains, with a record low temperature of -20.1°C on 23 August, 2013 and typical winter lows of between -5°C and -15°C during cold spells.
Snow in the Eastern Cape, Free State and KwaZulu-Natal
A cut-off low system has already blanketed parts of the Eastern Cape, Free State and KwaZulu-Natal in snow.
Yesterday was the coldest day of the year in Gauteng according to the South African Weather Service. Temperatures are expected to start easing from tomorrow afternoon.
Disruptive snow is forecast in parts of the Free State and the Eastern Cape and wet conditions over all provinces except Limpopo and the North West.
Gauteng residents can expect cloudy and cold conditions, with isolated showers and rain in the south and cool weather in the extreme north.
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