**Recent model consensus and observed rapid intensification position the 2026–27 El Niño as likely very strong on the Relative Oceanic Niño Index (RONI), which isolates the Niño 3.4 sea-surface temperature anomaly relative to the broader tropical ocean mean and rescales it to match traditional variance.** As of mid-August 2026, the event has already strengthened markedly, with conventional weekly Niño 3.4 anomalies near +2.7 °C and seasonal RONI values climbing from moderate levels earlier in the summer. NOAA’s Climate Prediction Center August outlook assigns greater than 90% probability of a very strong peak (RONI ≥ +2.0 °C) during Northern Hemisphere fall and winter, alongside a 69% chance the October–December three-month RONI exceeds the +2.5 °C historic threshold. Multi-model ensembles, including IRI and GFDL SPEAR runs initialized in July–August, center the peak in the October–December window and show median RONI values near or above +2.6 °C, with the majority of members exceeding +2.5 °C. This trajectory stems from unusually rapid warming fueled by elevated subsurface heat content, persistent westerly wind anomalies, and a strongly negative Southern Oscillation Index, outpacing most prior events at comparable stages. Traders therefore price the over-2.5 outcome highest, reflecting the weight of official forecasts and the low likelihood of substantial weakening before the seasonal maximum. New monthly model updates and subsurface observations through early fall remain the key near-term variables that could shift probabilities within the very-strong range.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedWhat will the peak RONI be for the 2026–27 El Niño?
What will the peak RONI be for the 2026–27 El Niño?
Over 2.5 60%
2.25–2.5 19%
2.0–2.25 11.3%
1.5–2.0 9%
NEW
NEW
Mar 31, 2027
Under 1.5
4%
1.5–2.0
9%
2.0–2.25
12%
2.25–2.5
19%
Over 2.5
60%
Over 2.5 60%
2.25–2.5 19%
2.0–2.25 11.3%
1.5–2.0 9%
NEW
NEW
Mar 31, 2027
Under 1.5
$200 Vol.
4%
1.5–2.0
$278 Vol.
9%
2.0–2.25
$65 Vol.
12%
2.25–2.5
$1,023 Vol.
19%
Over 2.5
$186 Vol.
60%
This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is below +1.5°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is at least +1.5°C and below +2.0°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is at least +2.0°C and below +2.25°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is at least +2.25°C and below +2.5°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is +2.5°C or above. Otherwise, it resolves "No". This market resolves "Yes" as soon as NOAA publishes a RONI value of +2.5°C or above for any listed season. If no listed season reaches +2.5°C, this market resolves "No" once NOAA has published the RONI value for DJF 2026-27.
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.**Recent model consensus and observed rapid intensification position the 2026–27 El Niño as likely very strong on the Relative Oceanic Niño Index (RONI), which isolates the Niño 3.4 sea-surface temperature anomaly relative to the broader tropical ocean mean and rescales it to match traditional variance.**
As of mid-August 2026, the event has already strengthened markedly, with conventional weekly Niño 3.4 anomalies near +2.7 °C and seasonal RONI values climbing from moderate levels earlier in the summer. NOAA’s Climate Prediction Center August outlook assigns greater than 90% probability of a very strong peak (RONI ≥ +2.0 °C) during Northern Hemisphere fall and winter, alongside a 69% chance the October–December three-month RONI exceeds the +2.5 °C historic threshold.
Multi-model ensembles, including IRI and GFDL SPEAR runs initialized in July–August, center the peak in the October–December window and show median RONI values near or above +2.6 °C, with the majority of members exceeding +2.5 °C. This trajectory stems from unusually rapid warming fueled by elevated subsurface heat content, persistent westerly wind anomalies, and a strongly negative Southern Oscillation Index, outpacing most prior events at comparable stages.
Traders therefore price the over-2.5 outcome highest, reflecting the weight of official forecasts and the low likelihood of substantial weakening before the seasonal maximum. New monthly model updates and subsurface observations through early fall remain the key near-term variables that could shift probabilities within the very-strong range.
This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is below +1.5°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.
Market Opened: Aug 17, 2026, 3:17 PM ET
Volume
$1,752End Date
Apr 1, 2027Market Opened
Aug 17, 2026, 3:17 PM ETResolver
0x69c47De9D...This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is below +1.5°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is at least +1.5°C and below +2.0°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is at least +2.0°C and below +2.25°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is at least +2.25°C and below +2.5°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is +2.5°C or above. Otherwise, it resolves "No". This market resolves "Yes" as soon as NOAA publishes a RONI value of +2.5°C or above for any listed season. If no listed season reaches +2.5°C, this market resolves "No" once NOAA has published the RONI value for DJF 2026-27.
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.**Recent model consensus and observed rapid intensification position the 2026–27 El Niño as likely very strong on the Relative Oceanic Niño Index (RONI), which isolates the Niño 3.4 sea-surface temperature anomaly relative to the broader tropical ocean mean and rescales it to match traditional variance.**
As of mid-August 2026, the event has already strengthened markedly, with conventional weekly Niño 3.4 anomalies near +2.7 °C and seasonal RONI values climbing from moderate levels earlier in the summer. NOAA’s Climate Prediction Center August outlook assigns greater than 90% probability of a very strong peak (RONI ≥ +2.0 °C) during Northern Hemisphere fall and winter, alongside a 69% chance the October–December three-month RONI exceeds the +2.5 °C historic threshold.
Multi-model ensembles, including IRI and GFDL SPEAR runs initialized in July–August, center the peak in the October–December window and show median RONI values near or above +2.6 °C, with the majority of members exceeding +2.5 °C. This trajectory stems from unusually rapid warming fueled by elevated subsurface heat content, persistent westerly wind anomalies, and a strongly negative Southern Oscillation Index, outpacing most prior events at comparable stages.
Traders therefore price the over-2.5 outcome highest, reflecting the weight of official forecasts and the low likelihood of substantial weakening before the seasonal maximum. New monthly model updates and subsurface observations through early fall remain the key near-term variables that could shift probabilities within the very-strong range.
This market resolves "Yes" if the peak RONI for the 2026–27 El Niño is below +1.5°C. Otherwise, it resolves "No".
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.
The peak RONI is the single highest Regional Ocean 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 reported in official NOAA CPC RONI updates (https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/).
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.
Volume
$1,752End Date
Apr 1, 2027Market Opened
Aug 17, 2026, 3:17 PM ETResolver
0x69c47De9D...**Recent model consensus and observed rapid intensification position the 2026–27 El Niño as likely very strong on the Relative Oceanic Niño Index (RONI), which isolates the Niño 3.4 sea-surface temperature anomaly relative to the broader tropical ocean mean and rescales it to match traditional variance.** As of mid-August 2026, the event has already strengthened markedly, with conventional weekly Niño 3.4 anomalies near +2.7 °C and seasonal RONI values climbing from moderate levels earlier in the summer. NOAA’s Climate Prediction Center August outlook assigns greater than 90% probability of a very strong peak (RONI ≥ +2.0 °C) during Northern Hemisphere fall and winter, alongside a 69% chance the October–December three-month RONI exceeds the +2.5 °C historic threshold. Multi-model ensembles, including IRI and GFDL SPEAR runs initialized in July–August, center the peak in the October–December window and show median RONI values near or above +2.6 °C, with the majority of members exceeding +2.5 °C. This trajectory stems from unusually rapid warming fueled by elevated subsurface heat content, persistent westerly wind anomalies, and a strongly negative Southern Oscillation Index, outpacing most prior events at comparable stages. Traders therefore price the over-2.5 outcome highest, reflecting the weight of official forecasts and the low likelihood of substantial weakening before the seasonal maximum. New monthly model updates and subsurface observations through early fall remain the key near-term variables that could shift probabilities within the very-strong range.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
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