Drop in global temperatures unlikely this summer: WMO

WMO forecasts a 50% chance of neutral or La Nina conditions from June to August, with La Nina chances increasing to 70% by August-November.

There is 50% chance of either neutral conditions or a transition to La Nina between June and August, the World Meteorological Organisation’s Long-Range Forecasts say, with the chance of La Nina conditions increasing to 60% during July-September and 70% during August-November.

People rest under the shade of a bridge to shelter from the scorching Sun, in Prayagraj on Monday. (AFP)

But despite this, WMO does not expect any major drop in land surface or sea surface temperatures during the next few months.

“Every month since June 2023 has set a new temperature record — and 2023 was by far the warmest year on record. The end of El Nino does not mean a pause, in long-term climate change as our planet will continue to warm due to heat-trapping greenhouse gases. Exceptionally high sea surface temperatures will continue to play an important role during next months,” WMO Deputy Secretary-General Ko Barrett said in a statement.

The past nine years have been the warmest on record even with the cooling influence of a multi-year La Nina from 2020 to early 2023, WMO warned. El Nino peaked in December 2023 as one of the five strongest on record.

“Our weather will continue to be more extreme because of the extra heat and moisture in our atmosphere. This is why the Early Warnings for All initiative remains WMO’s top priority. Seasonal forecasts for El Nino and La Nina and the anticipated impacts on the climate patterns globally are an important tool to inform early warnings and early action,” said Ko Barrett, who is leading a WMO delegation at the UN Climate Change session in Bonn.

The latest Global Seasonal Climate Update of WMO projects that widespread above-normal sea surface temperatures in all areas are expected to persist outside the near-equatorial eastern Pacific Ocean. There is therefore widespread prediction of above-normal temperatures over almost all land areas until July.

Predictions for rainfall are, in part, consistent with the typical impacts of the early stage of La Nina conditions, including above-normal rainfall in far northern South America, Central America, the Caribbean, northern Greater Horn of Africa and the Sahel, parts of southwest Asia and central Maritime Continent.

La Nina refers to the large-scale cooling of the ocean surface temperatures in the central and eastern equatorial Pacific Ocean, coupled with changes in the tropical atmospheric circulation, namely winds, pressure and rainfall. The effects of each La Nina event vary depending on the intensity, duration, time of year when it develops, and the interaction with other modes of climate variability. In many locations, especially in the tropics, La Nina produces the opposite climate impacts to El Nino.

In India, an El Nino is associated with harsher summer and weaker monsoon. La Nina, meanwhile, is associated with strong monsoon and above average rains, and colder winters.

“Yes, the El Nino hangover may remain for some more days till La Nina gets strong. But for us once the monsoon sets in, temperatures should come down. In June, models are suggesting onset may be delayed therefore we should expect high temps in June over northern parts of the country,” said M Rajeevan, former secretary, ministry of earth sciences and climate scientist responding to the WMO forecast.