The Effect of Climate Change on South Africa’s Winter Weather Patterns

What is happening to SA’s winters and is climate change playing a significant role? Vox Meteorologist Michelle du Plessis tells us more.

Data shows that winter temperatures across southern Africa have been steadily rising since the 1960s, with fewer days of frost and freezing conditions.

According to the NOAA, extreme cold events are now far less common – and when they do happen, they’re generally milder than in the past.

In the Western Cape, where winter rainfall is vital, climate models show that the rainy season is becoming shorter and more variable.

While some winters still bring strong cold fronts and good rainfall, others are marked by long dry spells.

The WMO warns that drought risks are increasing, especially in Mediterranean-type climates like the south-western Cape.

Interestingly, while total rainfall may decrease, when storms do occur, they may be more intense – bringing short bursts of heavy rain rather than steady soaking periods. This is because warmer air holds more moisture, which can lead to more powerful frontal systems when they develop.

Recent studies suggest that mid-latitude frontal systems – the cold fronts that bring winter rain – may grow stronger under climate change. However, this doesn’t mean we’ll get more of them. Instead, we may see fewer, but more intense, winter storms, followed by longer dry periods in between.

What this means for South Africa

In short, South African winters are becoming:

  • Warmer, with fewer frost days;
  • More variable, with rain falling in short, intense bursts; and
  • Less predictable, meaning long-range planning is harder.

A Note on Snow Forecasting at Vox Weather

Some early snow forecasts recently circulated on social media suggested possible snowfall over parts of Gauteng, North West, the Highveld, and other areas that rarely experience snow during late July. At Vox Weather, we chose not to post about these projections – and here’s why.

Advanced snow forecasts, particularly more than five days ahead, are often subject to significant change. In fact, updated model guidance today NO LONGER indicates snowfall over these north-eastern regions at all.

Our approach as meteorologists to snow forecasting involves more than just looking at model snowfall outputs.

We analyse:

  • The SYNOPTIC SYSTEM expected (e.g. a cold front or cut-off low);
  • The availability and timing of PRECIPITATION; and
  • The FREEZING LEVELS (the altitude at which temperatures are cold enough for snow to form and reach the ground).

These factors must all align for snowfall to be possible. A shift in any of them can lead to significant changes in where snow may fall – or if it occurs at all.

As of the latest forecast, we see:

  • A cold front expected to move in on Friday 25 July.
  • A strong ridging high-pressure system to follow, introducing colder air over southern South Africa during the weekend of 26 and 27 July.
  • Forecast snowfall now largely restricted to the Eastern Cape, Lesotho, the southern Free State, and adjacent high-lying areas.

At Vox Weather, we prefer to wait until we see consistency in multiple forecast runs – usually within a five-day window – before communicating potential snowfall.

 

This ensures that our updates are as accurate and reliable as possible.

Snow Patrol!

The arrival of snow isn’t an everyday occurrence for most of South Africa.

As we find ourselves back in snow season, we sat down with Vox Meteorologist Michelle du Plessis to give us the lowdown on how snow is formed.

And it turns out that, for snow to fall and reach the ground, three main weather conditions must come together.

Cold air from top to bottom: The air must be below freezing (0 °C) all the way from the clouds to the ground. If there’s a warmer layer in between, the snow will melt and fall as rain or sleet. Ideal snow forms in clouds where temperatures are between -10 °C and -20 °C.

Enough moisture in the air: Cold air alone isn’t enough – you also need moisture so that water vapour can form ice crystals. Dry air, even if freezing, won’t produce snow.

Something to lift the air: Snow usually forms when air is forced to rise, cool, and condense. This can happen with cold fronts, low-pressure systems like cut-off lows, or when air is pushed up over mountains.

Gauteng’s last snowfall: July 2023…

In July 2023, Gauteng experienced rare snowfall – something locals hadn’t seen in over a decade (before 2023 it snowed in 2012 and 1996). While light snow sometimes falls in the province, heavier events like this happen only once every 10 to 20 years. So yes, it was unusual, but not unheard of.

The July 2023 cold snap wasn’t driven by climate change – instead, it was the result of a powerful cold front that swept across the entire country and extended into our neighbouring countries – supported by a steep upper-air trough, pushing icy air far north.

Looking ahead to winter 2025…

We find that the odds of another snowfall in Gauteng remain low. Climate trends suggest snow in the region will become even rarer in future. That said, nature still has surprises.

If the right weather patterns align—such as a strong cold front or cut-off low pressure system – we could see isolated snow again. But it would remain the exception, not the rule.