Thomas Lamb · June 10, 2026 · Japan Meteorological Agency — Official Record
It Has Begun.
JMA Declares El Niño
Today. June 10, 2026.
Japan Meteorological Agency · El Niño Monitoring Report No. 405 · Issued 14:00 JST June 10, 2026
Source: https://www.jma.go.jp/jma/press/2606/10b/elnino202606.html
At 14:00 JST today, the Japan Meteorological Agency issued Monitoring Report No. 405 — a formal declaration that El Niño has begun. Not a watch. Not a probability forecast. A declaration. The JMA, one of the world's most rigorous meteorological authorities, has put its name on a start date: spring 2026.
The report projects El Niño continuing through autumn with 100% probability — the highest confidence rating the JMA uses. It forecasts the Niño monitoring index rising further through winter, when El Niño events typically reach their peak intensity.
Below is the full data from the JMA report, translated and visualised, with context from the framework laid out in this series.
Official JMA Declaration — Monitoring Report No. 405
エルニーニョ現象が発生しているとみられます
"El Niño is considered to have occurred"
Issued: June 10, 2026 (Reiwa 8) — Japan Meteorological Agency, Atmospheric and Ocean Department
Official finding: El Niño characteristics have appeared in both ocean and atmosphere across the equatorial Pacific. El Niño is considered to have begun from spring 2026.
Forecast: El Niño will continue through autumn — 100% probability. El Niño often develops and reaches peak intensity heading into winter. During El Niño winters, temperatures near Japan tend to run above normal.
Next report: July 10, 2026 at 14:00 JST
Key Data Points — May 2026 Actuals
Niño Monitoring Index (May)
+1.2°C
Above baseline. Threshold for El Niño declaration is +0.5°C sustained for 6 months. Already more than double the threshold.
5-Month Moving Average (Mar)
+0.4°C
Rising trend continuous. The 5-month average just crossed the +0.5°C declaration threshold — triggering today's official announcement.
Southern Oscillation Index (May)
−1.5
Sharply negative — from +1.3 in November to −1.5 in May. Negative SOI = weakening trade winds = El Niño atmospheric coupling confirmed.
Continuation Probability
100%
JMA projects El Niño persisting through autumn 2026 at maximum confidence. Further development toward winter peak expected.
12-Month Niño Monitoring SST Record — Jun 2025 to May 2026
The JMA report contains the full monthly SST record for the Niño monitoring region (NINO.3). The numbers below are the actual figures from Report No. 405 — the raw data behind today's declaration.
| Month | SST (°C) | Anomaly vs Baseline | SOI | Status |
|---|---|---|---|---|
| Jun 2025 | 26.4 | −0.2°C | +0.7 | Below baseline |
| Jul 2025 | 25.8 | −0.1°C | +0.9 | Near normal |
| Aug 2025 | 24.9 | −0.3°C | +0.6 | Below baseline |
| Sep 2025 | 24.4 | −0.5°C | 0.0 | La Niña boundary |
| Oct 2025 | 24.5 | −0.5°C | +1.2 | La Niña boundary |
| Nov 2025 | 24.5 | −0.5°C | +1.3 | La Niña boundary |
| Dec 2025 | 24.5 | −0.6°C | −0.2 | Below baseline — trough |
| Jan 2026 | 25.2 | −0.4°C | +0.9 | Turning point |
| Feb 2026 | 26.5 | +0.1°C | +1.0 | Crossing baseline ↑ |
| Mar 2026 | 27.5 | +0.3°C | +1.0 | Rising rapidly ↑ |
| Apr 2026 | 28.3 | +0.7°C | −0.6 | El Niño threshold crossed ↑ |
| May 2026 | 28.4 | +1.2°C | −1.5 | ⚠ DECLARATION ↑ |
SST Anomaly Trend — The Acceleration
The speed of this transition from La Niña boundary (−0.6°C in December) to El Niño declaration (+1.2°C in May) — 1.8°C in five months — is the key story in this data.
Zero line at 42% | El Niño threshold: +0.5°C sustained | Source: JMA Monitoring Report No. 405
The Turning Point — What Triggered This
The JMA report identifies exactly what flipped the system. From December 2025 through January 2026, the Niño monitoring index was sitting at its coolest point — −0.6°C, near La Niña boundary conditions. The Southern Oscillation Index was strongly positive (+1.3 in November), meaning trade winds were robust, holding warm water against the western Pacific near Indonesia and the Philippines.
Then the SOI collapsed — from +1.3 in November to −1.5 in May. A 2.8-point reversal in six months. The trade winds weakened dramatically across the central Pacific. The warm water that had been piled up against Indonesia's doorstep began its eastward migration. The Kelvin wave we documented in the previous posts is visible in the JMA's subsurface cross-section data — warm water at depth, moving east along the equator, from the Indian Ocean through to the central Pacific.
From JMA Report No. 405 — Key Translated Findings
Ocean state: SSTs across the entire equatorial Pacific are above normal, centred on the central and eastern Pacific. Subsurface ocean temperatures are also above normal across the full equatorial Pacific — centred on the central and eastern sections. The subsurface warm water is moving eastward.
Atmosphere state: Convective activity near the International Date Line is near normal, but lower-level easterly trade winds across the central equatorial Pacific are weaker than normal — the classic El Niño atmospheric signature now confirmed.
Western Pacific (Indonesia/Philippines region): Western Pacific tropical SSTs were near baseline in May. Forecast to fall below baseline through autumn. This is the heat drain — as El Niño builds eastward, the western Pacific cools below normal, suppressing rainfall over Indonesia and the Philippines.
Indian Ocean: Tropical Indian Ocean SSTs were below baseline in May. Forecast to remain near or below baseline through summer, then near or slightly above baseline in autumn.
Model forecast: The ocean-atmosphere coupled model projects the Niño monitoring SST continuing to rise through autumn, maintaining above-baseline values — driving El Niño to its peak intensity in winter 2026–27.
The western Pacific — the region above Earth's most volcanically active seafloor — is now forecast to run below its temperature baseline through autumn. The heat it accumulated over years has been declared officially absent. El Niño has claimed it.
— Thomas Lamb, interpreting JMA Report No. 405 within the submarine volcanic frameworkEverything That Happened Today
June 10, 2026 — The Timestamp
▸ 07:00 JST — Magnitude 7.8 earthquake strikes off Mindanao, Philippines. Tsunami warning issued across southern Philippines, northern Indonesia, Malaysian Sabah.
▸ Morning — NMME July 2026 SST anomaly forecast published showing blazing orange-red across equatorial Pacific. Prof. Eliot Jacobson publishes Niño 3.4 chart showing 2026 tracking near top of 44-year envelope.
▸ 14:00 JST — Japan Meteorological Agency issues Monitoring Report No. 405. Official declaration: El Niño has begun. Continuation through autumn: 100% probability.
▸ Background — 318 million people in crisis hunger. Fertilizer prices up 80%. Ocean Observatories Initiative being dismantled. NOAA research arm gutted. Tambora on elevated alert.
▸ Peak window — Winter 2026–27. Strongest El Niño in recorded history now the central forecast scenario.
What The JMA Data Adds To The Framework
The JMA report contains one line that deserves particular attention in the context of this series: the western Pacific tropical SST is forecast to run below baseline through autumn. This is the confirmation of the mechanism described in the previous posts.
The western Pacific warm pool — built over years, heated from above by solar radiation and trade winds, and from below by geothermal and hydrothermal activity from the most volcanically active seafloor on Earth — is now being drained. The JMA's coupled ocean-atmosphere model shows the warm water moving eastward along the equatorial subsurface, exactly as the Kelvin wave mechanism predicts.
What the JMA model does not account for — what no current operational forecast model accounts for — is the geothermal contribution to that warm pool's initial heat content. The question raised in 2004 remains open: how much of the energy now propagating eastward across the Pacific as the most powerful El Niño in living memory originated not from the atmosphere above, but from the mantle below?
Today's declaration does not answer that question. But it gives it an official start date. The experiment is now running. The data — what remains of it, after the OOI dismantling — will eventually tell us.
On The Record
June 10, 2026. That is the date on record. The JMA has spoken. The El Niño that will define the next 18 months of human history — its food systems, its weather patterns, its coral reefs, its monsoons, its wildfires — officially began in spring 2026 and was declared today.
The next JMA monitoring report will be issued July 10, 2026. By then, the system will have developed further. The Niño index will be higher. The trade wind weakening will be more pronounced. The western Pacific cooling — the drought signal for Indonesia and the Philippines — will be more visible.
We will be watching. With whatever instruments remain.
The Convergence Series — Thomas Lamb
Part I: Climate Science Revisited (2004) →
Part II: The Furnace Below — Magma, Ocean Heat & El Niño
Part III: Indonesia SST Deep Dive — 41 Years of Data
Part IV: Going Blind — Dismantling NOAA During a Super El Niño
Part V: It Has Begun — JMA Official Declaration, June 10 2026 (this post)
