**Strong model consensus on an exceptionally intense peak drives the 69.5% market-implied odds for a record 2026–27 El Niño.** As of mid-September 2026, NOAA’s Climate Prediction Center reports weekly Niño-3.4 sea surface temperature anomalies near +2.9 °C and climbing, with a greater than 90% chance the event reaches “very strong” status (≥ +2.0 °C) through winter 2026–27. Multi-model ensembles, including 667 runs analyzed by Carbon Brief and others, place the median peak near +3.6 °C in November–December—well above the 2015–16 record of roughly +2.75 °C—while roughly 91% of projections exceed prior maxima. NOAA assigns about 69–75% probability to a historic outcome exceeding every event since 1950 on the Relative Oceanic Niño Index (RONI). Rapid intensification fueled by a large subsurface heat reservoir and persistent westerly wind anomalies underpins the outlook, though final ranking depends on the precise three-month peak and index choice. Further model updates and observational data through the expected October–December maximum will refine these probabilities.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · UpdatedWill the 2026–27 El Niño be the strongest on record?
Will the 2026–27 El Niño be the strongest on record?
78% chance
NEW
NEW
Mar 31, 2027
78% chance
NEW
NEW
Mar 31, 2027
This market will resolve to "Yes" if the peak RONI for the 2026–27 El Niño is above 2.40°C, the highest Relative Oceanic Niño Index (RONI) value on record. Otherwise, this market will resolve to "No".
The peak RONI is the single highest 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. The record to beat is +2.40°C, set in DJF 1982-83, the highest RONI value for any three-month season in CPC's record. A peak RONI of exactly 2.40°C ties the record and resolves this market to "No".
The first published RONI value for each listed season is final and governs this market's resolution. This market may resolve immediately upon NOAA's first publication of a RONI value of above 2.40°C for any listed season.
If CPC's RONI dataset becomes temporarily unavailable, this market may be extended for up to 7 days. If CPC's RONI dataset is permanently discontinued, a consensus of credible reporting may be used. If the dataset remains unavailable after 7 days and there is no consensus of credible reporting, this market resolves to "No".
No subsequent revision to a season's value will be considered or will change the outcome once that season's first value has been published. The +2.40°C threshold is fixed for the purposes of this market; any later revision to a historical season's RONI value will not change it.
The resolution source for this market is the official NOAA CPC RONI updates, available here: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/**Strong model consensus on an exceptionally intense peak drives the 69.5% market-implied odds for a record 2026–27 El Niño.** As of mid-September 2026, NOAA’s Climate Prediction Center reports weekly Niño-3.4 sea surface temperature anomalies near +2.9 °C and climbing, with a greater than 90% chance the event reaches “very strong” status (≥ +2.0 °C) through winter 2026–27. Multi-model ensembles, including 667 runs analyzed by Carbon Brief and others, place the median peak near +3.6 °C in November–December—well above the 2015–16 record of roughly +2.75 °C—while roughly 91% of projections exceed prior maxima. NOAA assigns about 69–75% probability to a historic outcome exceeding every event since 1950 on the Relative Oceanic Niño Index (RONI). Rapid intensification fueled by a large subsurface heat reservoir and persistent westerly wind anomalies underpins the outlook, though final ranking depends on the precise three-month peak and index choice. Further model updates and observational data through the expected October–December maximum will refine these probabilities.
This market will resolve to "Yes" if the peak RONI for the 2026–27 El Niño is above 2.40°C, the highest Relative Oceanic Niño Index (RONI) value on record. Otherwise, this market will resolve to "No".
The peak RONI is the single highest 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. The record to beat is +2.40°C, set in DJF 1982-83, the highest RONI value for any three-month season in CPC's record. A peak RONI of exactly 2.40°C ties the record and resolves this market to "No".
The first published RONI value for each listed season is final and governs this market's resolution. This market may resolve immediately upon NOAA's first publication of a RONI value of above 2.40°C for any listed season.
If CPC's RONI dataset becomes temporarily unavailable, this market may be extended for up to 7 days. If CPC's RONI dataset is permanently discontinued, a consensus of credible reporting may be used. If the dataset remains unavailable after 7 days and there is no consensus of credible reporting, this market resolves to "No".
No subsequent revision to a season's value will be considered or will change the outcome once that season's first value has been published. The +2.40°C threshold is fixed for the purposes of this market; any later revision to a historical season's RONI value will not change it.
The resolution source for this market is the official NOAA CPC RONI updates, available here: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/
The peak RONI is the single highest 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. The record to beat is +2.40°C, set in DJF 1982-83, the highest RONI value for any three-month season in CPC's record. A peak RONI of exactly 2.40°C ties the record and resolves this market to "No".
The first published RONI value for each listed season is final and governs this market's resolution. This market may resolve immediately upon NOAA's first publication of a RONI value of above 2.40°C for any listed season.
If CPC's RONI dataset becomes temporarily unavailable, this market may be extended for up to 7 days. If CPC's RONI dataset is permanently discontinued, a consensus of credible reporting may be used. If the dataset remains unavailable after 7 days and there is no consensus of credible reporting, this market resolves to "No".
No subsequent revision to a season's value will be considered or will change the outcome once that season's first value has been published. The +2.40°C threshold is fixed for the purposes of this market; any later revision to a historical season's RONI value will not change it.
The resolution source for this market is the official NOAA CPC RONI updates, available here: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/
Market Opened: Sep 14, 2026, 11:23 AM ET
Volume
$663End Date
Apr 1, 2027Market Opened
Sep 14, 2026, 11:23 AM ETResolver
0x65070BE91...This market will resolve to "Yes" if the peak RONI for the 2026–27 El Niño is above 2.40°C, the highest Relative Oceanic Niño Index (RONI) value on record. Otherwise, this market will resolve to "No".
The peak RONI is the single highest 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. The record to beat is +2.40°C, set in DJF 1982-83, the highest RONI value for any three-month season in CPC's record. A peak RONI of exactly 2.40°C ties the record and resolves this market to "No".
The first published RONI value for each listed season is final and governs this market's resolution. This market may resolve immediately upon NOAA's first publication of a RONI value of above 2.40°C for any listed season.
If CPC's RONI dataset becomes temporarily unavailable, this market may be extended for up to 7 days. If CPC's RONI dataset is permanently discontinued, a consensus of credible reporting may be used. If the dataset remains unavailable after 7 days and there is no consensus of credible reporting, this market resolves to "No".
No subsequent revision to a season's value will be considered or will change the outcome once that season's first value has been published. The +2.40°C threshold is fixed for the purposes of this market; any later revision to a historical season's RONI value will not change it.
The resolution source for this market is the official NOAA CPC RONI updates, available here: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/**Strong model consensus on an exceptionally intense peak drives the 69.5% market-implied odds for a record 2026–27 El Niño.** As of mid-September 2026, NOAA’s Climate Prediction Center reports weekly Niño-3.4 sea surface temperature anomalies near +2.9 °C and climbing, with a greater than 90% chance the event reaches “very strong” status (≥ +2.0 °C) through winter 2026–27. Multi-model ensembles, including 667 runs analyzed by Carbon Brief and others, place the median peak near +3.6 °C in November–December—well above the 2015–16 record of roughly +2.75 °C—while roughly 91% of projections exceed prior maxima. NOAA assigns about 69–75% probability to a historic outcome exceeding every event since 1950 on the Relative Oceanic Niño Index (RONI). Rapid intensification fueled by a large subsurface heat reservoir and persistent westerly wind anomalies underpins the outlook, though final ranking depends on the precise three-month peak and index choice. Further model updates and observational data through the expected October–December maximum will refine these probabilities.
This market will resolve to "Yes" if the peak RONI for the 2026–27 El Niño is above 2.40°C, the highest Relative Oceanic Niño Index (RONI) value on record. Otherwise, this market will resolve to "No".
The peak RONI is the single highest 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. The record to beat is +2.40°C, set in DJF 1982-83, the highest RONI value for any three-month season in CPC's record. A peak RONI of exactly 2.40°C ties the record and resolves this market to "No".
The first published RONI value for each listed season is final and governs this market's resolution. This market may resolve immediately upon NOAA's first publication of a RONI value of above 2.40°C for any listed season.
If CPC's RONI dataset becomes temporarily unavailable, this market may be extended for up to 7 days. If CPC's RONI dataset is permanently discontinued, a consensus of credible reporting may be used. If the dataset remains unavailable after 7 days and there is no consensus of credible reporting, this market resolves to "No".
No subsequent revision to a season's value will be considered or will change the outcome once that season's first value has been published. The +2.40°C threshold is fixed for the purposes of this market; any later revision to a historical season's RONI value will not change it.
The resolution source for this market is the official NOAA CPC RONI updates, available here: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/
The peak RONI is the single highest 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. The record to beat is +2.40°C, set in DJF 1982-83, the highest RONI value for any three-month season in CPC's record. A peak RONI of exactly 2.40°C ties the record and resolves this market to "No".
The first published RONI value for each listed season is final and governs this market's resolution. This market may resolve immediately upon NOAA's first publication of a RONI value of above 2.40°C for any listed season.
If CPC's RONI dataset becomes temporarily unavailable, this market may be extended for up to 7 days. If CPC's RONI dataset is permanently discontinued, a consensus of credible reporting may be used. If the dataset remains unavailable after 7 days and there is no consensus of credible reporting, this market resolves to "No".
No subsequent revision to a season's value will be considered or will change the outcome once that season's first value has been published. The +2.40°C threshold is fixed for the purposes of this market; any later revision to a historical season's RONI value will not change it.
The resolution source for this market is the official NOAA CPC RONI updates, available here: https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/
Volume
$663End Date
Apr 1, 2027Market Opened
Sep 14, 2026, 11:23 AM ETResolver
0x65070BE91...**Strong model consensus on an exceptionally intense peak drives the 69.5% market-implied odds for a record 2026–27 El Niño.** As of mid-September 2026, NOAA’s Climate Prediction Center reports weekly Niño-3.4 sea surface temperature anomalies near +2.9 °C and climbing, with a greater than 90% chance the event reaches “very strong” status (≥ +2.0 °C) through winter 2026–27. Multi-model ensembles, including 667 runs analyzed by Carbon Brief and others, place the median peak near +3.6 °C in November–December—well above the 2015–16 record of roughly +2.75 °C—while roughly 91% of projections exceed prior maxima. NOAA assigns about 69–75% probability to a historic outcome exceeding every event since 1950 on the Relative Oceanic Niño Index (RONI). Rapid intensification fueled by a large subsurface heat reservoir and persistent westerly wind anomalies underpins the outlook, though final ranking depends on the precise three-month peak and index choice. Further model updates and observational data through the expected October–December maximum will refine these probabilities.
Experimental AI-generated summary referencing Polymarket data. This is not trading advice and plays no role in how this market resolves. · Updated
Beware of external links.
Beware of external links.
Frequently Asked Questions