What Is EL Niño? Why Ocean Temperatures Reach Near Record Highs In April

Climate scientists are sounding the alarm as global sea surface temperatures in April 2026 reached the second-highest levels ever recorded for the month.

According to data from the European Union’s Copernicus Climate Change Service, extrapolar ocean temperatures averaged 21.0°C (69.8°F), narrowly trailing the all-time April record set in 2024. This spike signals a rapid transition into a new El Niño phase, with forecasters warning of a “one-in-four chance” that this cycle could develop into a rare and devastating “Super El Niño.”

The emergence of these conditions follows closely on the heels of the 2023–2024 El Niño, which helped propel 2024 to become the hottest year in recorded history. Typically, these cycles occur every two to seven years, but the current pace of warming has surprised experts. Samantha Burgess, strategic lead at Copernicus, noted that the data from April 2026 is a “clear signal of sustained global warmth,” characterized by widespread marine heatwaves and a continued decline in Arctic sea ice—all indicators of a climate increasingly dictated by extreme shifts.

What a ‘Super’ El Niño Means for 2026-2027

A “Super” El Niño is defined by an even more dramatic rise in sea surface temperatures in the tropical Pacific, which can fundamentally alter global weather patterns. If this “once-in-a-century” event manifests, meteorologists anticipate a significant injection of heat into the atmosphere, potentially pushing global average temperatures well beyond the 1.5°C warming limit established by the Paris Agreement. This could lead to an unprecedented surge in extreme weather events, ranging from catastrophic wildfires in Australia to intensified hurricane seasons and prolonged droughts in parts of Asia and Africa.

While the natural El Niño-Southern Oscillation (ENSO) cycle is responsible for these fluctuations, scientists emphasize that human-caused global warming is acting as a force multiplier. The baseline temperature of the oceans is already significantly higher than in previous decades, meaning each new El Niño starts from a “hotter” floor. As the world watches the Pacific, the focus remains on how quickly global infrastructure can adapt to a year that may shatter the heat records recently set in 2024 and 2025.