A US weather forecaster pegged the likelihood of the El Nino weather phenomenon occurring during the Northern Hemisphere autumn and winter at 60-65 per cent in its monthly update on Thursday.

The Climate Prediction Centre (CPC), an agency of the National Weather Service, has begun dialling back its outlook for the phenomenon since going on El Nino watch earlier this year for the first time since 2012.

The agency had lowered its outlook to 65 per cent for an El Nino last month.

"At this time, the consensus of forecasters expects El Nino to emerge during September-October and to peak at weak strength during the late fall and early winter," CPC said in the report.

El Nino, the warming of sea surface temperatures in the Pacific, can cause flooding and heavy rains in the United States and South America and can trigger drought conditions in Southeast Asia and Australia. - Reuters