WMO: El Niño "Firmly Established and Strengthening Rapidly", Peak Expected Around December

WMO’s 8 Oct 2026 update says Niño 3.4 rose from about +1.6°C in June to +2.5°C in August, with an Oct–Dec average forecast near +3.7°C (a model consensus of 13 centres, not an observation) versus the prior record of +2.6°C in Nov 2015–Jan 2016. Peak is expected around December and persistence through Feb 2027 is near-certain; a positive Indian Ocean Dipole is expected to peak in October.