The El Niño Briefing #11: +3.3 °C, a third record week in a row
Updated: October 16, 2026 · 2 min read · Live dashboard
NOAA's weekly Niño 3.4 reached +3.3 °C for the week centred 7 October. Third record in a row: +3.1 °C, then +3.2 °C, now +3.3 °C. The file goes back to September 1981, 2,354 weeks, and no week outside this year got above +3.0 °C.
Four weeks ago it read +2.8 °C. That's half a degree in a month, at the top of the scale.
The Bureau has a record too. The Bureau of Meteorology's relative Niño 3.4, which takes out the warming of the tropical oceans as a whole, is at +2.81 °C for the week ending 11 October. The Bureau says that's the highest in its weekly series (which starts in 2008), above +2.78 °C for the week ending 22 November 2015. One correction: we gave the week before as +2.83 °C; the Bureau has since revised it to +2.81 °C, so the index held level rather than slipping.
Further east, still climbing. Niño 3 rose to +4.1 °C, from +4.0 °C. Its best week outside this year was +3.3 °C, in November 1997. Off Peru and Ecuador, Niño 1+2 eased to +5.2 °C from +5.3 °C, still well above the +4.5 °C of late June 1983. Niño 4, the western box, is +1.3 °C, short of its +1.7 °C record.
The same week in 1997 and 2015. Niño 3.4 read +2.0 °C in the week centred 8 October 1997 and +2.1 °C in the week centred 7 October 2015. Those events went on to peak at +2.3 °C (December 1997) and +3.0 °C (November 2015).
No new odds this week. CPC's 8 October discussion still stands: an 83% chance that October–December is stronger than any El Niño since 1950. The seasonal numbers haven't moved either: RONI +1.69 and ONI +2.16 °C for July–September. The next season, August–October, arrives with CPC's November update.
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Next. NOAA's weekly file updates on Monday 19 October with the week centred 14 October. CPC's next discussion is due on 12 November.
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