2026 Ocean Heat Records Show How Climate Change and El Niño Are Combining

The 2026 ocean-temperature records point to a compound climate event: human-caused warming has lifted the ocean’s long-term heat baseline, while a powerful El Niño is redistributing some of that stored heat toward the surface and atmosphere. El Niño is the short-term accelerator; greenhouse-gas warming is the hotter track on which it operates. 11721

What the 2026 ocean records actually show

A daily global sea-surface temperature average near 21.1°C was reported for the extra-polar oceans between 60°S and 60°N—an area that excludes most polar waters—and was a record for that time of year. Daily records and monthly records are not interchangeable, however.

The official monthly figures provide a clearer comparison:

• June 2026: 20.92 ± 0.10°C, the warmest June on record and above the previous June record from 2024. 3
• July 2026: 21.00 ± 0.11°C, the warmest July on record, exceeding July 2023’s 20.92 ± 0.06°C. 5
• Another report using Copernicus data gave July’s average as 20.96°C, compared with 20.89°C in July 2023. The small difference reflects dataset and measurement choices, not a different overall conclusion: July was exceptionally warm and set a monthly record. 26

That distinction matters because a single daily peak can be striking, but a monthly average shows that the warmth persisted across a much broader period.

Climate change sets the baseline; El Niño redistributes heat

El Niño is a naturally recurring climate pattern involving unusually warm surface waters in the tropical Pacific and associated changes in atmospheric circulation. It can move heat from the ocean into the atmosphere and alter rainfall and temperature patterns far beyond the Pacific.

Human-caused climate change works differently. Greenhouse gases have created a persistent planetary energy imbalance, and the ocean has absorbed more than 90% of the excess heat retained by that warming. 1 The result is a higher background temperature across the global ocean, not just in the Niño region.

When El Niño develops on that warmer baseline, its surface anomaly is added to an ocean that is already carrying unprecedented heat. This helps explain why 2026’s records are not confined to one tropical Pacific patch. Warmer water also increases evaporation and the amount of moisture available to the atmosphere, raising the potential for heat stress, intense rainfall and other extremes. 117

Why scientists are calling this El Niño historically powerful

The phrase “strongest in 150 years” describes a projection, not a completed observation. Forecasters expect tropical Pacific sea-surface temperatures to rise by more than 3°C above normal later in 2026. That would be far above the roughly 1–2°C rise typical of an El Niño event and beyond the range of modern observations in some forecasts. 323335

The Met Office has described the developing event as likely to be the strongest in living memory and probably the largest since the nineteenth century. NOAA forecasts cited in reporting have also placed the chance of a “very strong” event at roughly four in five by late 2026. 183233

Forecast confidence can change as the Pacific evolves. For that reason, “historic” should be treated as a forecast assessment until the event peaks and can be compared with earlier El Niño events using consistent measurements.

What the combined warming could mean for weather

El Niño reorganizes atmospheric circulation, so its effects vary by location. The same event can raise drought risk in some regions while increasing rainfall and storm risk in others. A warmer ocean adds energy and moisture to that circulation system, potentially increasing the severity of impacts.

Expected or reported risks include:

• more intense heat and humidity, including higher nighttime temperatures near warm coasts;
• heavier rainfall and a greater risk of flooding in regions affected by El Niño’s wet-weather pattern;
• drought and water stress in regions shifted toward drier conditions;
• conditions that can support stronger tropical cyclones in parts of the Pacific; and
• temporary changes in coastal sea level along parts of the eastern Pacific as warm water expands and winds and currents shift. 4102527

These mechanisms help explain why Pacific islands and coastal communities are closely watching the event. But they do not prove that any single hurricane, flood, drought or reported damage in places such as Hawaii, Panama, Puerto Rico or the U.S. Virgin Islands was caused by El Niño or climate change alone. Event-specific attribution requires analysis of the individual event against natural variability and the warmer climate baseline.

Why global heat records could continue into 2027

The atmosphere does not respond instantly to changes in ocean heat. Global temperatures can peak after El Niño strengthens because heat and moisture move through the coupled ocean–atmosphere system with a lag. A strong El Niño can therefore raise global temperatures after the initial ocean records have already been set. 14

Current forecasts differ on whether 2026 will surpass 2024 as the warmest calendar year. One estimate puts the chance at about 35%, while other reporting says the year could at least come close. 344146 The longer-range outlook is more consistent: the Met Office says it is “very likely” that 2027 will exceed 2024’s global temperature record, though that remains a probabilistic forecast rather than a certainty. 3233

The broader lesson is not that a natural climate cycle has suddenly replaced climate change. It is that natural variability can temporarily add a powerful pulse of heat to a world whose baseline has already been raised by human emissions. As the ocean continues to accumulate energy, future El Niño events will begin from a warmer starting point—even when the underlying cycle itself remains natural.

The bottom line

The 2026 ocean records reveal an interaction, not a choice between explanations. Human-caused warming supplies the long-term heat buildup; El Niño helps release and redistribute that heat, producing a sharper short-term rise in sea-surface and global air temperatures.

That combination is why a daily average near 21.1°C, record monthly values of 20.92°C in June and 21.00°C in July, and forecasts of a historically powerful El Niño matter beyond the numbers. They signal a higher risk of cascading heat, rainfall, drought and coastal impacts—and a strong possibility that the next major global temperature record will arrive in 2027. 351732