[12] An intense burst of typhoon activity subsequently took place between September and November 2013, which was thought to possibly be a precursor signal to an impending change of the Pacific climate towards El Niño rather than La Niña.

[9] During January 2014, after surveying various climate models, the World Meteorological Organization warned that there was an enhanced possibility of a weak El Niño event happening during 2014.

[9] A large area of atmospheric convection was present at a low latitude near the International Dateline, in association with the development of an unusual amount of early season tropical cyclones near the Marshall Islands.

[nb 2][16][17] Over the next few months, the atmosphere failed to respond in order to reinforce the developing El Niño, with the monsoon trough remaining weak and tropical cyclone activity slowing, while no episodes of strong westerly winds at a low latitude occurred.

[21] During their March 2015 diagnostic discussion, NOAA's CPC and the IRI reported that El Niño conditions had been observed during February 2015, after the above average sea surface temperatures had become weakly coupled with the tropical atmosphere.

In addition, another strong westerly wind burst event took place around July as a result of twin tropical cyclones straddling the equator.

"[29] In mid November, NOAA reported that the temperature anomaly in the Niño 3.4 region for the 3-month average from August to October 2015 was the 2nd warmest on record with only 1997 warmer.

[5][36] These anomalies included the traditional and equatorial Southern Oscillation indices becoming near zero, while atmospheric convection, upper and lower level winds all became near average.

[5] As a result of this the BoM, NOAA's CPC, IRI, and the JMA, all declared that the record-tying El Niño event had ended in late May/early June.

[45][46] Tropical Depression Nine-C subsequently formed in the Central Pacific on 31 December, whose remnants in turn contributed to the development of Hurricane Pali on 7 January.

The El Niño event affected millions of people around the world, including in Africa, Central America, Southeast Asia, and the Pacific Islands.

[50] The combination of heat and low rainfall brought a very early start to the 2015–16 Australian bushfire season, with over 125 fires burning in Victoria and Tasmania during October.

[50] The El Niño event enhanced the 2015 short rains season between October and December 2015, with more rainfall than normal falling in eastern Africa.

[50] However, the event failed to end the long term dryness, despite some regions including Pacifica receiving heavy rain which led to mudslides.

[60] As El Niño conditions started to develop during early 2014, sea levels in western Micronesia including in waters surrounding the island nations of Palau and Guam dropped by 6–9 feet (1.8–2.7 m).

[63] In Maguindanao, many rice and corn fields were destroyed by the drought brought by El Niño, and soon, the provincial government declared a state of calamity in the province.

[64] Earlier, North Cotabato declared a state of calamity,[65] and the provincial government's aid to the farmers suffering from the drought caused a protest and a clash with police in Kidapawan.

[66] Iloilo, Guimaras, General Santos, Isabela, Quirino, Bukidnon, Davao del Sur, Basilan, Bohol, and Cebu declared a state of calamity due to Typhoon Melor.

[63][67][68][69] Cửu Long Droughts and saltwater infiltration were considered to be particularly serious, the worst within the last 100 years, causing severe damage to the western provinces.