To understand why El Niño is important in 2023, look back to Cape Town’s “day zero”

2023 is firmly on track to be the hottest year in the books, thanks, in part, to a rapidly strengthening El Niño weather pattern. And we’re only just getting started. Globally, El Niño, coupled with climate change-related weather variations, will usher in new, record-breaking temperatures in the next five years (2023-2027), as well as disruptive weather and climate events, according to the World Meteorological Organisation. 

Some of the most recent major El Niños have provoked the greatest droughts, tropical storms, floods, forest fires and coral bleaching events of the past 50 years. And the impact of these events extends beyond rising temperatures. A few other knock-on effects include higher food and energy prices, shortages of goods and a loss of export revenues if production is negatively affected by changing weather patterns. All of this can even trigger social unrest; particularly across emerging economies, which are typically harder hit by unpredictable weather events.

Caused by cyclical shifts in the water temperature of the Pacific Ocean, El Niño is a periodic — and predictable – global climate phenomenon that adds more heat and moisture to the climate system. The last strong El Niño weather event occurred in 2014-2016 and helped make 2016 the current hottest year on record.  

Just ask the citizens of Cape Town, a port city on South Africa’s southwest coast, which experienced a one-in-400 year drought between 2015 and 2018. Unsurprisingly, this massive decline in rainfall meant that Cape Town came close to becoming the first major city in the world to run out of drinkable water. Often dubbed the "day-zero" drought because of suggestions that municipal water supplies would have to be largely switched off and residents would need to queue for daily rations of water, the extreme weather patterns Cape Town experienced during this time were caused by El Niño conditions.

A look at data from Africa Data Hub’s Climate Observer reveals how temperatures increased and how drastically the city’s rainfall dropped during this period. In November 2018, for example, Cape Town temperatures soared to 3.77 degrees Celsius above the historical average. This was the highest temperature deviation experienced by the City between July 2012 and July 2022. 

Cape Town typically gets most of its rain in the winter months – June, July and August – but during this drought, rainfall figures fell well below average. For example, in June 2014, the City received around 212.2mms of rain. In June 2018, these numbers dropped to 66.3mms. Similarly, in July 2013, Cape Town’s rainfall stood at 167.6mms but dropped to just 29.2mms in the same month in 2017. Luckily for the 4.6 million residents of Cape Town, the City was able to avoid "day-zero" thanks to a combination of sustained and strategic water saving campaigns and initiatives and public support for water usage targets. Cape Town also invested in and deployed different technologies, like pressure management solutions, for example, which were used to increase distribution efficiency and curb wastage.

With this year well on the way to being our warmest in history and some scientists suggesting that 2023 may just be a preamble to even hotter years ahead, it is imperative that governments, policymakers, businesses and civil society work together to ensure that we all survive and thrive beyond this period of extreme weather activity. 

Think the weather in your region is unusual this year? Compare historical records for African locations in the African Climate Observer.