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

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

icon for What 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 76%

2.25–2.5 23%

2.0–2.25 3.6%

1.5–2.0 <1%

Polymarket

$11,321 Vol.

Over 2.5 76%

2.25–2.5 23%

2.0–2.25 3.6%

1.5–2.0 <1%

Polymarket

$11,321 Vol.

Under 1.5

$696 Vol.

<1%

1.5–2.0

$898 Vol.

1%

2.0–2.25

$1,527 Vol.

4%

2.25–2.5

$3,005 Vol.

23%

Over 2.5

$5,195 Vol.

76%

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 official NOAA CPC/IRI outlooks have driven the strong market tilt toward a peak RONI exceeding 2.5°C, reflecting rapid intensification of the 2026–27 El Niño. Equatorial Pacific sea surface temperature anomalies have strengthened markedly, with the conventional weekly Niño 3.4 index reaching +2.6°C in mid-August while the relative RONI stands near +1.0°C seasonally. Forecasts center the peak in October–December 2026, assigning greater than 90% probability to a very strong event (≥ +2.0°C RONI) and 69% odds of a historic peak surpassing prior events since 1950. Ensemble runs from multiple dynamical models show unusually consistent signals for exceptional intensity, with many projecting values well above 2.5°C. Traders appear to be pricing in these verified observational trends and updated seasonal guidance ahead of the next monthly outlook release.

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.
Volume
$11,321
End Date
Apr 1, 2027
Market Opened
Aug 17, 2026, 3:17 PM ET

Resolution Source

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/

Resolver

0x69c47De9D...
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.
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 official NOAA CPC/IRI outlooks have driven the strong market tilt toward a peak RONI exceeding 2.5°C, reflecting rapid intensification of the 2026–27 El Niño. Equatorial Pacific sea surface temperature anomalies have strengthened markedly, with the conventional weekly Niño 3.4 index reaching +2.6°C in mid-August while the relative RONI stands near +1.0°C seasonally. Forecasts center the peak in October–December 2026, assigning greater than 90% probability to a very strong event (≥ +2.0°C RONI) and 69% odds of a historic peak surpassing prior events since 1950. Ensemble runs from multiple dynamical models show unusually consistent signals for exceptional intensity, with many projecting values well above 2.5°C. Traders appear to be pricing in these verified observational trends and updated seasonal guidance ahead of the next monthly outlook release.

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.
Volume
$11,321
End Date
Apr 1, 2027
Market Opened
Aug 17, 2026, 3:17 PM ET

Resolution Source

https://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso/roni/

Resolver

0x69c47De9D...
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.

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Frequently Asked Questions

"What will the peak RONI be for the 2026–27 El Niño?" is a prediction market on Polymarket with 5 possible outcomes where traders buy and sell shares based on what they believe will happen. The current leading outcome is "Over 2.5" at 76%, followed by "2.25–2.5" at 23%. Prices reflect real-time crowd-sourced probabilities. For example, a share priced at 76¢ implies that the market collectively assigns a 76% chance to that outcome. These odds shift continuously as traders react to new developments and information. Shares in the correct outcome are redeemable for $1 each upon market resolution.

As of today, "What will the peak RONI be for the 2026–27 El Niño?" has generated $11.3K in total trading volume since the market launched on Aug 17, 2026. This level of trading activity reflects strong engagement from the Polymarket community and helps ensure that the current odds are informed by a deep pool of market participants. You can track live price movements and trade on any outcome directly on this page.

To trade on "What will the peak RONI be for the 2026–27 El Niño?," browse the 5 available outcomes listed on this page. Each outcome displays a current price representing the market's implied probability. To take a position, select the outcome you believe is most likely, choose "Yes" to trade in favor of it or "No" to trade against it, enter your amount, and click "Trade." If your chosen outcome is correct when the market resolves, your "Yes" shares pay out $1 each. If it's incorrect, they pay out $0. You can also sell your shares at any time before resolution if you want to lock in a profit or cut a loss.

The current frontrunner for "What will the peak RONI be for the 2026–27 El Niño?" is "Over 2.5" at 76%, meaning the market assigns a 76% chance to that outcome. The next closest outcome is "2.25–2.5" at 23%. These odds update in real-time as traders buy and sell shares, so they reflect the latest collective view of what's most likely to happen. Check back frequently or bookmark this page to follow how the odds shift as new information emerges.

The resolution rules for "What will the peak RONI be for the 2026–27 El Niño?" define exactly what needs to happen for each outcome to be declared a winner — including the official data sources used to determine the result. You can review the complete resolution criteria in the "Rules" section on this page above the comments. We recommend reading the rules carefully before trading, as they specify the precise conditions, edge cases, and sources that govern how this market is settled.