What will the peak RONI be for the 2026–27 El Niño?

Polymarket prediction market· Same prices, rules and result

Polymarket prices · as of 07:35 UTCCloses Apr 1, 2027Polymarket 24h vol $2.2K

Polymarket chance · top 4 of 5 options

Over 2.5 70%2.25–2.5 26%2.0–2.25 3%1.5–2.0 <1%

5 options · in level order

Option24hAI analystsTiers 1–2Buy

Under 1.5<1%———

1.5–2.0<1%———

2.0–2.253%———

2.25–2.526%———

Over 2.570%———

5 open levels, in level order.

Rules Polymarket's rules · the same for all 5 options

This market resolves based on the peak RONI — the single highest Relative Oceanic Niño Index (RONI) value reported by NOAA's Climate Prediction Center (CPC) across the overlapping three-month seasons ASO 2026, SON 2026, OND 2026, NDJ 2026-27, and DJF 2026-27, as published in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/). See each individual market for its bracket and full resolution terms. This market may resolve immediately once NOAA has published a RONI value that determines the peak: the "Over 2.5" outcome resolves "Yes" as soon as any listed season reaches +2.5°C or above. Any other outcome will not be confirmed until NOAA publishes the DJF 2026-27 value, since RONI can still rise in a later season and DJF captures El Niño's typical peak-strength window. The first published RONI value for each listed season is final and governs resolution; no subsequent revision to a season's value will change the outcome once that season's first value has been published. If CPC's RONI dataset is permanently discontinued, other information from NOAA may be used.Show rulesHide rules

Resolution criteria: This market resolves based on the peak RONI — the single highest Relative Oceanic Niño Index (RONI) value reported by NOAA's Climate Prediction Center (CPC) across the overlapping three-month seasons ASO 2026, SON 2026, OND 2026, NDJ 2026-27, and DJF 2026-27, as published in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/). See each individual market for its bracket and full resolution terms. This market may resolve immediately once NOAA has published a RONI value that determines the peak: the "Over 2.5" outcome resolves "Yes" as soon as any listed season reaches +2.5°C or above. Any other outcome will not be confirmed until NOAA publishes the DJF 2026-27 value, since RONI can still rise in a later season and DJF captures El Niño's typical peak-strength window. The first published RONI value for each listed season is final and governs resolution; no subsequent revision to a season's value will change the outcome once that season's first value has been published. If CPC's RONI dataset is permanently discontinued, other information from NOAA may be used.