The Pacific Ocean is a giant network of nerve endings that warns of an impending attack a year in advance. In 2023–2024, El Niño, the warm phase of the Pacific climate oscillation, pushed global temperatures to record highs. Now, two independent methods, like two doctors examining the same symptoms, agree: no new attack in 2025.

The first method constructs a climate network with 14 nodes in the central and eastern equatorial Pacific and 193 nodes outside this region. Nodes are linked if their surface air temperature anomalies are strongly correlated. The average link strength S(t) rises in the year before El Niño onset and falls as it begins. The threshold Θ is set on the training period 1950–1980. In 2024, the average link strength remained well below the threshold.

The second method computes the sample system entropy (SysSampEn) over 22 nodes in the Niño3.4 region with a 5°×5° resolution. SysSampEn measures the complexity of temperature anomalies: low values indicate order, high values indicate disorder. In the year before El Niño, SysSampEn is typically high, while before a neutral year it is low. In 2024, SysSampEn was 0.79 against a threshold of 1.31.

Both methods produced a consistent forecast: no El Niño in 2025, with probabilities of 91.2% from the climate network and 91.7% from SysSampEn. On historical data since 1981, the network method in its strict version has given 9 correct warnings out of 9, and its forecasts of no El Niño have been correct in 31 out of 34 cases. Combined with logistic regression on the ONI index, they give a 69.6% probability of a neutral phase and a 21.8% probability of La Niña for the November–January 2025/26 season. This is notably higher than the probability of a neutral outcome from the official NOAA CPC forecast (44% for August–October 2025).

So the network of nerve connections in the Pacific Ocean has once again shown its strength. It not only warns of an approaching attack but also gives time to prepare. For agriculture, energy, and water management, this means the ability to plan a year without undue alarm. And if the forecast holds, global temperatures after the record 2024 will likely recede slightly.