As recent weather shows, South Africans can experience dramatically different weather conditions on the same day, with one province melting in hot temperatures while another experiences cold, cloudy or rainy conditions.
Although the country shares the same broad seasonal patterns, its weather is influenced by several factors, including geography, altitude, wind direction, air masses and the movement of weather systems.
The result is that temperatures can vary between provinces, and even between areas within the same province.
So why does this happen?
Different factors influence SA's weather
There are several factors influencing the unpredictable and vastly different weather.
1. South Africa’s geography plays a major role
South Africa has a varied landscape, from the high-altitude interior plateau to the low-lying coastal regions.
Johannesburg and Pretoria, for example, are situated on the Highveld, where altitude influences temperatures. Coastal cities such as Durban and Cape Town experience different conditions because of their proximity to the ocean.
The ocean can moderate temperatures, which means coastal areas remain cooler during hot spells and warmer during some cold spells than inland areas.
However, it's worth noting that coastal weather can also change quickly when winds shift, or cold fronts move through.
2. Cold fronts do not affect the entire country equally
Cold fronts moving in from the Atlantic Ocean often bring cooler temperatures, increased cloud cover, rain and strong winds to parts of the Western and Southern Cape.
As a front moves eastwards, its effects may reach other parts of the country, but not necessarily at the same time or with the same intensity.
One region may therefore experience a sharp drop in temperatures while another remains warm under clearer skies.
The timing and strength of a weather system are important in determining which areas experience cold, rain or warmer conditions.
3. Different wind directions bring different temperatures
Winds transport air from one area to another, and the characteristics of that air influence local weather.
A wind blowing from a cooler ocean can lower temperatures along parts of the coast. In contrast, winds bringing air from warmer inland areas can contribute to hotter conditions.
The direction of the wind, the source of the air mass and whether the air is rising or sinking all influence the temperature experienced at ground level.
4. Cloud cover makes a difference
Clouds affect how much solar energy reaches the Earth's surface.
Under clear skies, the sun can heat the ground more efficiently during the day. Where thick cloud cover develops, less sunlight reaches the surface, often keeping daytime temperatures lower.
Cloudy, rainy conditions associated with a cold front can therefore leave one region feeling considerably colder than an area experiencing sunshine at the same time.
5. Altitude affects temperatures
Higher-altitude areas are generally cooler than lower-lying areas, all else being equal.
This is one reason temperatures in parts of the Highveld and mountainous regions can differ from those in low-lying areas.
However, altitude alone does not determine the weather. Wind, cloud cover, rainfall and the position of weather systems can all influence whether a particular area experiences unusually warm or cold conditions.
Does this mean the seasons are changing?
This is not necessarily the case. Different weather conditions across the country do not, on their own, indicate a change in the seasons or climate.
Seasonal patterns provide the broader background, but day-to-day weather depends on the movement of air masses, fronts, pressure systems and local geographical conditions.
A hot spell in one province and cold conditions in another can occur within the same season, as we have seen in recent weeks.
South Africa's varied landscape and the movement of weather systems mean there is no single temperature that describes conditions across the entire country.
While one region may experience heat under sunny skies, another may be affected by a cold front, cooler ocean air or cloud cover.
IOL