This contract asks what the highest Relative Oceanic Niño Index (RONI) value will be for the 2026-27 El Niño. The market is listed on Polymarket and is organized as a set of brackets, each with its own Yes and No contract. The event's resolution rules tie the outcome to values published by NOAA's Climate Prediction Center (CPC) [1]. The market is grouped under the Climate category [1]. The contract resolves on the peak RONI, defined as the single highest RONI value that NOAA CPC reports across five overlapping three-month seasons: ASO 2026, SON 2026, OND 2026, NDJ 2026-27, and DJF 2026-27 [1]. The rules say these values appear in official NOAA CPC RONI updates [1]. Each bracket asks whether the peak falls within a particular range, such as 2.5 or above, at least 2.25 but below 2.5, or below 1.5 [1]. The contract has an early-resolution feature for the top bracket. Under the rules, the bracket labeled "Over 2.5" resolves Yes as soon as any listed season reaches +2.5 degrees C or above [1]. The other brackets cannot be confirmed until NOAA publishes the DJF 2026-27 value, because RONI can still rise in a later season and DJF covers the typical peak-strength window of El Niño [1]. The rules also state that the first published RONI value for each season is final, so later revisions to that season's value will not change the outcome [1]. If CPC permanently discontinues the RONI dataset, the rules allow other NOAA information to be used [1]. The market's listed end time is 2027-04-01T03:59:00.000Z [1]. This is a date written into the contract terms. It is not an announced publication date for any NOAA value, and the actual resolution depends on when CPC publishes the relevant seasonal values.

Historical Context

Wikipedia describes the 2026-2027 El Niño as an ongoing event whose onset the WMO declared on 2 June 2026. It also says the event has been classified as a "very strong El Niño," also known as a Super El Niño, and that it is expected to peak in November or December and last through early 2027 [2]. These statements are historical background from an encyclopedia entry and do not confirm the present status of the event. Wikipedia's article on Super El Niño events explains that these are very strong El Niño events, in which average sea surface temperatures in parts of the Pacific rise by 2 degrees Celsius or more [3]. The same article says that as of September 2026 there had been six Super El Niño events in recorded history [3]. Its description of climate impacts, including flooding, drought, and crop failures, is general background [3].

Frequently Asked Questions