El Nino: NOAA Puts It at 2.0 Degrees, a Tenth Behind 1997 - and Gives It an 83 Percent Chance to Pass Every Event Since 1950

El Nino reached +2.0 degrees Celsius on NOAA's official index for August to October 2026, the second-highest reading for that time of year since records began in 1950. Only the 1997-98 event, one of the strongest on record, was higher at the same point, by a tenth of a degree. The figure comes from the Relative Oceanic Nino Index, which NOAA's Climate Prediction Center uses as its principal measure of El Nino strength; in its weekly update of November 9, the center put the August-October value at 2.0 degrees, with the full data table giving it as +1.97, compared with +2.07 for August-October 1997. NOAA forecasters have put the chance that it surpasses every El Nino since 1950 by the end of the year at 83 percent. The latest values are provisional - NOAA notes they may change up to two months after they are first posted, so a gap this small could still shift.

The 2026 event has tracked just behind 1997-98 for months, and the gap narrowed in the latest reading: 0.14 degrees behind in June-August, 0.15 behind in July-September, and 0.10 behind in August-October. The current event has already moved past 2015-16 for this time of year - that El Nino stood at +1.80 in August-October 2015 and peaked at +2.25 that winter - while the highest three-month value in NOAA's record, +2.40, was set in December-February 1982-83. On the traditional measure, which does not subtract the background warming of the tropics as a whole, 2026 is further ahead: the traditional Oceanic Nino Index for August-October 2026 was +2.46, against +2.04 in 1997, and the weekly traditional Nino 3.4 anomaly was +3.3 in the week centred on November 4. NOAA has not declared a record, because on its official relative index the 1982-83 peak still stands.

The center's official forecast, in its October 8 ENSO discussion, said the chances 'remain high for a historic event' that would exceed the strength of every El Nino since 1950, which it defines as a three-month index value of +2.5 or more - an 83 percent chance for October-December and 70 percent for November-January. The center expects a strong to very strong El Nino to last through January-March 2027, with El Nino persisting through March-May 2027 and neutral conditions favoured by April-June, and the CFS.v2 forecast model, run on November 9, also favours El Nino continuing through the Northern Hemisphere winter. The center's next monthly ENSO discussion is due November 12 and will update the record odds.

For Houston, the number that matters is not the record watch - it is the winter map NOAA has already drawn from this event. NOAA's U.S. Winter Outlook, released October 15, shows El Nino likely influencing December 2026 through February 2027, with wetter-than-average conditions likely across the southern United States, from California to Florida, warmer-than-average temperatures across the northern U.S., and drought improving for the majority of the country, including the Southern Great Plains. National Weather Service Director Ken Graham said a very strong El Nino will likely bring a southward and eastward shift to the jet stream, which tilts the odds toward stormier weather across the South. The center cautions that an event of this size makes the typical El Nino impacts more likely, though not guaranteed - the typical winter pattern is a more active storm track across the southern U.S. and milder, drier conditions across much of the north. The Weather Prediction Center updates its three-month outlook monthly, with the next update on November 19.