This year's El Nino is on track to be the strongest in at least 70 years, further increasing the likelihood of widescale disruption to global agricultural markets.

The likelihood of El Nino persisting through February 2027 is now close to 100%, according to new forecasts from the World Meteorological Organization, a UN agency.

"Never before has the UN weather agency issued such an unequivocal forecast for El Nino or its cooler counterpart, La Nina," the Geneva, Switzerland-based body said.

Strong El Nino events can lead to extreme heat and irregular rainfall across the globe, impacting harvests for goods from sugar to wheat.

"El Nino's effects are very much with us," analysts at Rabobank wrote in a note.

Concerns about the impact of the weather system are helping to drive a range of commodity prices higher, the analysts said.

Corn prices--which are also boosted by disruption to supply from the Black Sea--are up around 33% from their late-June low.

"Concerns are growing that El Nino could reduce [corn] production in South America...which could further tighten global stocks," the Rabobank analysts said.

Sugar crops in Asia and South America are also set to face significant disruption as a result of El Nino, with lower-than-usual levels of rainfall expected in India, and the inverse in Brazil, potentially hurting crops.

"The expected strength of El Nino increases the likelihood that such effects materialize," the Rabobank analysts said. Sugar trades up around 23% from its late-July low at 18 cents a pound.

Further disruption as a result of this year's particularly strong El Nino is likely, Barclays analysts wrote in a note.

"Historical El Nino events have often been associated with significant moves in weather-​sensitive markets," they said.

Temperatures in parts of the Pacific Ocean were more than eight degrees Celsius above normal in July and early August, the UN said. A reading of 2 degrees Celsius above average is enough to constitute a very strong or extreme El Nino, according to the WMO.

"The question is no longer whether El Nino will strengthen, but how much heat--and disruption--it will leave behind," said Celeste Saulo, head of the WMO.