The official ocean index says this is not an El Niño. The RONI reading for April–June 2026 is +0.47, which sits below the +0.50 threshold that would classify the cycle as anything other than Neutral. If your climate exposure review stops at that headline, it records a quiet season. The sub-national water balance says otherwise.
Neutral is a label about the ocean, not about your borrowers
ENSO indices describe the state of the tropical Pacific. They are useful, and they are deliberately coarse: one number, for one ocean, for a three-month window. A risk book is none of those things. It is a set of specific places, each with its own rainfall, its own evaporative demand, and its own tolerance for a dry quarter.
The gap shows up immediately when you put the two side by side. The basin is Neutral. The land is not.
What the land is reading
SPEI-3 measures the last three months of water balance — precipitation against evaporative demand — relative to the same season in the historical baseline. Zero is normal for the time of year. Negative is drier than that baseline, and readings past −0.5 are the conventional line where a dry spell stops being noise.
Counting the grid cells past that line, in a season the headline index calls Neutral:
| Country | Cells with SPEI-3 < −0.5 | Share |
|---|---|---|
| Thailand | 272 of 718 | 37.9% |
| Vietnam | 579 of 1,132 | 51.1% |
| Malaysia | 272 of 698 | 39.0% |
Just over half of Vietnam’s cells are past the line. Close to two in five of Thailand’s and Malaysia’s are. That is the distribution underneath a single word — and the word does not carry it.
Why an average cannot tell you this
A national average would round this away. If a third of a country is dry and the rest is not, the mean lands somewhere unremarkable, and the unremarkable number is the one that reaches the committee. The share of area past a threshold survives that rounding: it answers how much of the map is affected, which is the question a portfolio actually asks.
It also travels differently across a book. Thirty-eight per cent of Thailand is not thirty-eight per cent of any given lender’s Thai exposure. Whether those cells sit under irrigated land, rain-fed smallholders, or a reservoir catchment is what turns a share into a loss estimate — and that is a question you can only ask of sub-national data.
What this means for credit, insurance and water
Credit. A Neutral classification is not evidence that agricultural borrowers had a normal quarter. The evidence is the water balance where the collateral is.
Insurance. Parametric triggers written against a basin-scale index and losses driven by local water balance are two different distributions. A Neutral season with a third of the map past −0.5 is exactly where that basis risk shows up.
Water. Allocation decisions are made per catchment. A national or oceanic label has no catchment in it.
The next reading is not in yet
The RONI value for June–August 2026 is pending and is expected around 5 September. Until it publishes, the honest position is that the ocean signal for that window is unknown — which is a further argument for watching the land directly rather than waiting on a label to tell you whether to look.
Neutral is a statement about the Pacific. Whether your exposure had a dry season is a different question, asked in a different place, and it has to be measured there.
Updated 13 August 2026 — the May 2026 figures on this page were revised after the underlying drought files were recomputed on 9 August 2026. The grid-cell totals are unchanged. How we version and re-verify our data, including the full record of this revision, is set out on our methodology page.
GlobMaps builds sub-national climate intelligence for South-East Asia — province and grid-cell level drought signals across Thailand, Vietnam and Malaysia. Learn more at globmaps.com.