A year of ocean heat and a powerful El Niño could break the global temperature record.
What is known.
Copernicus reports September 2026 was the second-warmest September in ERA5 and 1.63°C above its pre-industrial reference.
The question in this article is narrower than the general hazard: YES only if the first Copernicus C3S annual 2026 global temperature summary, published by 15 February 2027, ranks 2026 first in the ERA5 calendar-year record. Ties do not count. The source documents what was known at publication, not proof that the forecast has come true.
What earlier cases show.
The current reference point comes from Copernicus C3S's published record. Forecasts of disasters can fail because a risk signal is not a local outcome, and because official reporting and verification can lag real-world events.
Why it is a possibility.
September was already the second-warmest September in ERA5, and the tropical Pacific is warming into year-end.
Earlier cool months can keep the full-year average below 2024 even if late 2026 is extraordinary.
How the 38% was assessed.
Reference point. The published 38% is an editorial judgment from the Copernicus C3S evidence available on 15 October 2026, not a measured frequency for this exact event.
Why it could be higher. September was already the second-warmest September in ERA5, and the tropical Pacific is warming into year-end.
Why it could be lower. Earlier cool months can keep the full-year average below 2024 even if late 2026 is extraordinary.
The editorial judgment. A 38% point estimate allows the defined event a real possibility by 2027-02-15 while respecting the countercase. The probability is frozen at publication for scoring.
Limits of the estimate. Official data can be delayed or revised, and a broad regional warning does not settle a specific event. The original rule and deadline control the result; a later evidence update may change the displayed current estimate without rewriting this article.
What could prevent it.
Earlier cool months can keep the full-year average below 2024 even if late 2026 is extraordinary.
How it will be assessed.
YES only if the first Copernicus C3S annual 2026 global temperature summary, published by 15 February 2027, ranks 2026 first in the ERA5 calendar-year record. Ties do not count.
Sources and primary records
Probabilities are provisional editorial estimates, not guarantees. Sources document the present evidence and resolution rule. Read the full disclaimer.