Imagine two thermometers in a house. One reads freezing, the other reads a thaw. Whom do you trust? It is the same with the El Niño forecast for 2026: two forecasting methods gave different answers.
The first method tracks how temperatures at different points in the Pacific Ocean change together. If they start moving too synchronously, it resembles a crowd of people suddenly marching in step. Such synchronization often precedes El Niño, a warm current that alters weather worldwide. In 2025, the ocean showed no such synchronization, and the method says El Niño is almost certainly a no-show in 2026.
The second method looks at the "jitteriness" of temperature at a single ocean point. If the temperature starts behaving unpredictably, like a person before a big event, it could signal an approaching El Niño. This method suggests a weak El Niño is likely in 2026.
Rather than argue over which method is right, scientists looked at history: over the past 40 years, there have been six cases where the methods diverged in this same way. In two of those cases, El Niño did indeed arrive. Hence the probability: 2 out of 6, or about 37.5%. That is lower than the official forecast of 61%, and it is an honest answer: we still do not know how the ocean will decide to behave.
Laplace's rule, used to combine the forecasts, was formulated in the 18th century to estimate the probability of the sun rising. Here it is applied to climate events, highlighting the link between classical probability theory and modern climatology.