If there is a single weather pattern that strikes fear into agricultural and soft commodities markets, it is El Niño.The recurring climatic event – caused by an increase of the water temperature in the tropical Pacific – has in the past triggered wild gyrations of wholesale food prices, as it usually brings droughts to south-east Asia and Australia.

Traders and agricultural officials are nervously watching weather models for the possible development of an El Niño later this year – on the cards after August – after several countries, including Australia and the US, issued early weather warnings.