The United Nations warned on Wednesday of a growing likelihood the weather phenomenon El Nino will develop in coming months, fuelling higher global temperatures and possibly new heat records.

The UN's World Meteorological Organization said it now estimated there was a 60-percent chance that El Nino would develop by the end of July, and an 80-percent chance it would do so by the end of September.

El Nino, which is a naturally occurring climate pattern typically associated with increased heat worldwide, as well as drought in some parts of the world and heavy rains elsewhere, last occurred in 2018-19.

Since 2020 though, the world has been hit with an exceptionally long La Nina – El Nino's cooling opposite – which ended earlier this year, ceding way to the current neutral conditions.

And yet, the UN has said the last eight years were the warmest ever recorded, despite La Nina's cooling effect stretching over nearly half that period.

Without that weather phenomenon, the warming situation could have been even worse.

La Nina "acted as a temporary brake on global temperature increase", WMO chief Petteri Taalas said in a statement.

"The development of an El Nino will most likely lead to a new spike in global heating and increase the chance of breaking temperature records," he warned.

At this stage, there is no indication of the strength or duration of the looming El Nino.

The last one was considered weak, but the one before that, between 2014 and 2016, was considered strong, with dire consequences.

WMO pointed out that 2016 was "the warmest year on record because of the 'double whammy' of a very powerful El Nino event and human-induced warming from greenhouse gases".

Since the El Nino effect on global temperatures usually plays out the year after it emerges, the impact will likely be most apparent in 2024, it said. (AFP)