2023–2024 El Niño event

El Niño is a natural climate event caused by the Southern Oscillation, popularly known as El Niño or also in meteorological circles as El Niño-Southern Oscillation or ENSO,^[6] through which global warming of the eastern equatorial Pacific Ocean results in the development of unusually warm waters between the coast of South America and the International Date Line. This phenomenon significantly affects the global average surface temperature of the planet. A large El Niño event can raise it by as much as a few tenths of a degree Celsius.^[9]

During an El Niño event, the east–west trade winds die, generating warmer air temperatures in the eastern and central parts of the tropical Pacific.^[10] Warmer temperatures lead to warming ocean surface temperatures, leading to heavier rainfall and flooding in the eastern Pacific.^[11][12] Since there are no trade winds, the necessary rains do not form in the western Pacific, generating droughts in Asia and Oceania.^[8] The phenomenon has a recurrence of between 2 and 7 years, and can last from 9 to 12 months.^[7][13]

The combination of El Niño and above-normal temperatures in the Atlantic Main Development Region (MDR) tends to favor increased hurricane activity in the eastern Pacific.^[14]

At the beginning of the year, it was considered that the climatic conditions of the first quarter of 2023 pointed to the occurrence of a strong El Niño event, similar to those that occurred in 1982, 1997, and 2015.^[15][16] In mid-January 2023, weather forecasts regarding the probable occurrence of the El Niño phenomenon in 2023 and 2024 were published in various media.^[17][18][19] Given that Earth's average temperature has already increased by 1.2 °C since pre-industrial times, a large enough El Niño event in 2023-2024 could even push the planet, temporarily, into warming greater than 1.5 °C.^{[20][21][22][2]}

On June 8, the National Oceanic and Atmospheric Administration (NOAA) of the United States confirmed the presence of El Niño.

During the month of June 2023 the global surface air temperature was warmer than the corresponding month of any previous year.

July 4 was declared the start date of the 2023-2024 El Niño event by the World Meteorological Organization (WMO).

On July 20, the government of India – the main rice exporter in the world – banned the export of non-basmati rice, in order to seek to contain the rise in prices at the domestic level and guarantee its availability in the domestic market in the face of the crisis, geopolitics, the climate crisis and the El Niño event.

During the month of July 2023 the global surface air temperature was warmer than the corresponding month of any previous year.

By early March 2024, pockets of below average Sea Surface Temperature SST Anomalies pierced the surface in the equatorial East Pacific, a clear sign that the El Niño event was in full retreat.^[23]

Several severe thunderstorms bringing high winds and pea-sized hail hit Los Angeles, California, causing strong flooding in streets.^[24]

In recent report, data from the Copernicus Climate Change Service showed that March 2024 was the warmest March on record around the globe. It was 1.68°C (3.02°F) warmer than pre-industrial times.^[25][26]

Compared to previously strong El Niño events like 1982–83, 1997–98, and 2014–16, tropical cyclone activity in the North Atlantic was not suppressed much by the strong El Niño due to record warm sea surface temperatures in the Atlantic.^[27][28] The 2023 season went on to become the fourth most active Atlantic Hurricane season on record tied with 1933, and set an all-time record high number of storms for an El Niño year.^[29] North Pacific tropical cyclone activity was more mixed. The North East Pacific was above average in terms of hurricanes, major hurricanes, and ACE, typical of previously strong El Niño event years, despite an exceptionally late start.^[30][31][32] The North West Pacific on the other hand observed well below average activity, mostly due to a consistently negative PDO environment, which suppressed the formation of a lot of tropical storms.^[33] While the activities in the North Pacific basins were a mixed bag, both basins proved to be extremely destructive in 2023, with Typhoon Doksuri in the North West Pacific and Hurricane Otis in the North East Pacific both causing more than $10 billion in damages.^[34][35]

World Meteorological Organization analyses indicated extreme heat and heatwave effects in central South America from August to December. Temperatures in parts of central Brazil exceeded 41 °C in August although that month marks the middle of the winter in the southern hemisphere.^[36]

Althouth droughts are common in the Amazon during El Niño events, studies indicate that global warming likely played a bigger role than the 2023-2024 El Niño event in the 2023 Amazon's record drought.^[37]

The 2024 Rio Grande do Sul floods in May of that year were caused by historical heavy rains and storms in the southern Brazilian state. Those events were considered by climatologists to had been intensified by the effects of climate change and the 2023–2024 El Niño event.^{[38] [39] [40]} The 2023 Rio Grande do Sul floods had already plagued the state in the month of September prior, a few months into the same El Niño event.

In April 2024, the India Meteorological Department (IMD) warned of heatwave conditions for 10 to 20 days in several parts of the country. The IMD said that the conditions would eventually subside with the onset of the neutral phase of the El Niño–Southern Oscillation and the monsoon in June.^[41]

On July 20, the Indian government banned the export of non-basmati rice, in order to seek to contain the rise in prices domestically and guarantee its availability in the domestic market due to the geopolitical scenario—especially the Russian invasion of Ukraine. , the effect of El Niño and the extreme weather conditions generated by the climate crisis in other rice-producing countries. This decision would affect more than 42 countries importing rice from India, especially Bangladesh, Nepal, Benin, Senegal, Costa de Ivory, Togo and Guinea. In 2022, India exported 10.3 million tons of non-basmati white rice, which represents a quarter of the total sales of the world's leading exporter of this grain.

During the month of August 2023, the absence of rain has been significant in general in the country, taking into account that August is the second rainiest of the year, after July, and during the monsoon. August 2023 is estimated to be the driest since meteorological parameters began to be recorded in 1901. In India, the impacts of El Niño develop in such a way that precipitation is suppressed in almost the entire country, except in the territories located in the east and northeast.

Oceania has been affected since the beginning of the year by the absence of east–west trade winds and the increase in the temperature of the waters of the eastern Pacific. Since there are no trade winds, the necessary rains do not form in the western Pacific, generating droughts in Asia and Oceania.

The months of May, July and August have been months of little rain. The long-term forecast is that from November to December 2023 there will be conditions with higher temperatures and drier weather. A greater number of forest fires are expected for spring than in recent years in the Northern Territory, Queensland and New South Wales, as well as regions of Victoria and South Australia.

El Niño causes severe flooding in East Africa, killing 300 people.