Warming Helped Strengthen Hurricane Polo as Much as El Niño Did, Study Finds
World Weather Attribution said Oct. 15, 2026, that human-caused warming made the ocean and air conditions capable of fueling a storm like Hurricane Polo about 23 times likelier than they would have been without that warming. The group reported that the same conditions were about 14 times likelier under the 2026 El Niño than under neutral Pacific conditions, and that climate change's effect was therefore at least as large as El Niño's.
The rapid analysis was published on the group's own site and is not peer-reviewed. It looks separately at the heaviest one-day rainfall where Polo came ashore, the sea temperatures the storm crossed before it peaked, and potential intensity, the strongest winds that ocean and air conditions could support.
On the rainfall, WWA reported what it could not settle. Observations show that one-day downpours like Polo's in the landfall region have become about 6 times as likely as the world has warmed, an increase the group calls extremely large and subject to very large uncertainties. Climate models do not reproduce that trend and many underestimate extreme rainfall in the region, which the group describes as a known problem there. WWA's conclusion is that it cannot quantify climate change's role in Polo's rainfall, though it notes that a rising trend is what the physics of a warmer atmosphere would predict.
The group reported that the sea surface temperatures Polo passed over before reaching its peak strength were about 1.4 °C warmer than in a preindustrial climate. Using a second method, it estimated that Polo's own peak wind speed was about 2.7 m/s higher than it would have been without human-induced warming.
Polo reached Category 5 off Mexico before coming ashore in Baja California Sur as a Category 2 hurricane in September 2026. The analysis was carried out by scientists in Mexico, the United States, the United Kingdom, Ireland and the Netherlands.
