Geneva: The United Nations' weather agency has warned that El Nino conditions are rapidly developing in the tropical Pacific, with an 80 per cent probability of emerging between June and August, raising concerns about droughts, heavy rainfall, and heatwaves across several parts of the world.

In its latest quarterly update released on Tuesday, the World Meteorological Organisation (WMO) said forecasts from its global network point to a significant shift toward El Nino conditions during the coming months.

"Fuelled by unusually warm ocean waters in the tropical Pacific, El Nino conditions are developing and are set to influence global temperature and rainfall patterns," the WMO said.

According to the agency, the probability of El Nino occurring during the June-August period has reached 80 per cent, while the likelihood rises to near or above 90 per cent by November. Most forecast models indicate the event is expected to be at least moderate in strength and could potentially become strong.

El Nino is a naturally occurring climate pattern characterised by above-average sea surface temperatures in the central and eastern equatorial Pacific Ocean. The phenomenon alters atmospheric circulation, influencing rainfall, temperatures, and weather systems around the globe. It generally occurs every two to seven years and lasts between nine and 12 months.

WMO Secretary-General Celeste Saulo urged governments and communities to prepare for its impacts.

"The world therefore needed to get ready for an El Nino which could 'exacerbate drought and heavy rainfall and increase the risk of heatwaves both on land and in the ocean'."

The agency noted that even a moderate El Nino can increase the likelihood of weather and climate extremes.

The previous El Nino episode contributed to record-breaking global temperatures, helping make 2023 the second-hottest year on record and 2024 the warmest year ever observed, with global temperatures reaching around 1.55 degrees Celsius above the 1850-1900 pre-industrial average.

Recent observations show sea-surface temperatures in the central-eastern equatorial Pacific nearing El Nino thresholds during late April and early May. Sub-surface ocean temperatures in the region were recorded at more than six degrees Celsius above average. Atmospheric indicators, including the Southern Oscillation Index, are also showing patterns consistent with the development of El Nino conditions.

While the WMO said there is no evidence that climate change directly increases the frequency or intensity of El Nino events, it warned that a warmer atmosphere and ocean can amplify their impacts by providing more energy and moisture for extreme weather events.

UN Secretary-General Antonio Guterres described the development as a major climate warning.

"El Nino is arriving on our doorstep," Guterres said in a video message.

"The world must treat it as the urgent climate warning it is. El Nino conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther, and cross borders with devastating speed.

"The only effective response is climate action equal to the crisis -- ending the addiction to fossil fuels, accelerating the shift to renewables, protecting the most vulnerable, and delivering early warning systems for all."

For the June-August period, the WMO forecasts above-normal temperatures across nearly all regions of the world. The agency warned that this could worsen drought conditions in areas already facing reduced rainfall and increase the risk of multiple climate-related hazards occurring simultaneously.

Regional climate outlooks suggest below-normal rainfall across the northern Greater Horn of Africa during its key June-September rainy season. South Asia is also expected to receive below-average monsoon rainfall, while Central America could experience drier and warmer-than-normal conditions.

The WMO added that warmer Pacific waters associated with El Nino may boost hurricane activity in the central and eastern Pacific during the Northern Hemisphere summer, while suppressing hurricane formation in the Atlantic Ocean.

The agency said advance warnings would help governments and communities strengthen preparedness measures, particularly in sectors vulnerable to climate fluctuations, including agriculture, water resources, energy, and public health.