A European bank has looked at South Africa’s weather forecast and decided it has something to say about the rand, which is either impressively thorough analysis or a sign that everything, eventually, becomes a currency story. Commerzbank has told investors that the upcoming El Nino weather pattern could lift inflation and put downward pressure on the rand, a warning that connects two things that do not, on the surface, look like they belong in the same sentence.
The mechanism is more straightforward than it first sounds. Inflation, the rate at which prices for goods and services rise, is a genuine driver of exchange-rate movements, since rising prices tend to make investors expect the South African Reserve Bank to raise interest rates in response, and that expectation itself moves currency markets well before any actual rate decision is made.
How weather becomes a currency story
El Nino is a climate phenomenon bringing hotter, drier conditions to southern Africa, and in past episodes it has reduced rainfall specifically across the country’s main grain-growing regions, leading to weaker harvests and, inevitably, higher food prices. Higher food costs feed directly into headline inflation, which already sits above the Reserve Bank’s 4.5% target even before any weather-driven shock arrives, meaning there is less room to absorb a bad harvest than there would be in a lower-inflation environment.
South Africa’s economy leans heavily on agriculture and commodity exports, so a weaker harvest means less domestic supply of staples like maize and wheat, pushing retail prices higher, while a drier climate simultaneously raises costs for water-intensive manufacturers. Both effects push the overall price level in the same direction at once, and when inflation expectations rise that way, the rand often weakens because the market is pricing in tighter monetary policy before it actually arrives. The currency is also sensitive to South Africa’s trade balance, and a drop in agricultural exports widens that deficit further, adding a second source of pressure on top of the first.
It is worth being clear-eyed about what Commerzbank has and has not actually said. This is a claim by the bank, not an independently verified forecast, and it comes without specific inflation numbers, a timeline for the expected impact, or any quantitative estimate of how far the rand might move. Weather-related risk notes like this one have become a recurring feature of bank research this year, and their value lies less in precision than in flagging a genuine risk worth watching rather than predicting its exact size.
For small and medium enterprises, the practical message is to keep an eye on input-cost trends, food-related products especially, and to weigh hedging strategies if currency exposure is significant enough to matter to the bottom line. Businesses importing raw materials or leaning on export markets will likely feel any real effect here more directly and sooner than a purely domestic-facing business would, and the eventual scale of the impact will depend entirely on how severe this El Nino episode actually turns out to be, and how quickly the Reserve Bank responds once it does.
El Nino events are not new to southern Africa, and the region has a genuine track record to draw on: the 2015 to 2016 episode, one of the strongest on record, triggered widespread crop failures across the region and contributed meaningfully to a spike in South African food inflation the following year. That history is precisely why a bank research note flags the pattern well in advance rather than waiting for harvest data to confirm the damage, since agricultural supply shocks take months to move from a dry planting season to an actual shortage on supermarket shelves, and businesses that plan around the lag rather than the eventual headline tend to manage the transition considerably better than those reacting only once prices have already moved.
