Signal View

What this ENSO event means on the ground, from Pacific ocean heat to regional impact — with the evidence behind every card one click away.

Some panels below still show placeholder data pending validation — see docs/data-sources.md

Regional impact

Updated 4 July 2026 Confidence: medium

Regional impact — New Zealand

Typical El Niño pattern: Strong El Niño events have historically been associated with drier, windier conditions on the east coast of both islands and increased drought risk in eastern regions, alongside wetter conditions in the west.

Current observation: El Niño conditions have now been reached in the tropical Pacific atmosphere and ocean, according to criteria assessed by Earth Sciences New Zealand. The event remains in its early stages; impacts on New Zealand’s weather patterns are yet to be fully felt but are anticipated later in the year.

Rainfall anomaly: Gisborne, Hawke's Bay, Wairarapa: rainfall totals are about equally likely to be below normal (40% chance) or near normal (35% chance) for the outlook period as a whole, but there is a risk of some significant rainfall occurring early in July. Coastal Canterbury and the nearby plains, east Otago: rainfall totals are about equally likely to be below normal (40% chance) or near normal (35% chance), for the outlook period as a whole, but there is a risk of some significant rainfall occurring early in July.

Land stress indicator: Gisborne, Hawke's Bay, Wairarapa: soil moisture and river flows are about equally likely to be near normal (40 - 45% chance) or below normal (40 - 45% chance). Coastal Canterbury and the nearby plains, east Otago: soil moisture and river flows are about equally likely to be below normal (45% chance) or near normal (40% chance).

What to watch next: NIWA's next Seasonal Climate Outlook, covering the quarter after July - September 2026.

Evidence & limitations
Source
NIWA Seasonal Climate Outlook
Last updated
4 July 2026
Data type
forecast
Limitations
  • "Typical pattern" is a historical tendency, not a guarantee for the current event.
  • Rainfall and land stress figures below are forecast probability statements, not measured anomalies.
Updated 4 July 2026 Confidence: medium

Regional impact — Australia

Typical El Niño pattern: Strong El Niño events have historically been associated with below-average rainfall and elevated drought and fire risk across much of eastern and southern Australia.

Current observation: Rainfall deficits are emerging across parts of the eastern states, consistent with the typical pattern for this stage of an El Niño episode.

Rainfall anomaly: Not yet available from a validated real source (placeholder figure, not a real number). BOM's website blocks all automated access — see docs/data-sources.md item 6 and docs/learnings/2026-07-04-bom-rainfall-fully-blocked.md.

Land stress indicator: not yet available

What to watch next: Whether the rainfall deficit spreads further west and how soil moisture responds heading into the drier season.

Placeholder data
Evidence & limitations
Source
Sample / Placeholder Data (local development only)
Last updated
4 July 2026
Data type
interpreted
Limitations
  • "Typical pattern" is a historical tendency, not a guarantee for the current event.
  • Rainfall and land stress figures are not yet available from a validated real source.
Updated 3 July 2026

Pacific SST anomaly

Pacific sea surface temperature anomaly map, updated 3 July 2026, showing surrounding coastlines (Asia, Australia, New Zealand, the Americas) for geographic context
Pacific SST anomaly · updated 3 July 2026 · diverging scale, blue = colder than average, red = warmer than average · placeholder visual, not real observational data
Updated 3 July 2026 Confidence: medium

ENSO status

+0.48°C Neutral ONI, MAM 2026 (3-month running mean)

The signal is strengthening. Conditions are consistent with ENSO-neutral. The Niño 3.4 index has been strengthening over the last three-month period.

Evidence & limitations
Source
NOAA CPC / ONI
Last updated
3 July 2026
Data type
observed
Limitations
  • ONI is a 3-month running mean; short-term weekly fluctuations are smoothed out.
  • Classification bands follow the standard NOAA ONI scale (see docs/methodology.md).
Updated 3 July 2026

ENSO forecast probability

El Niño Advisory issued 11 June 2026

El Niño conditions are present and expected to strengthen into the Northern Hemisphere winter 2026-27.

“63% chance of very strong El Niño during November-January”

Next official update expected 9 July 2026.

Evidence & limitations
Source
NOAA CPC ENSO Diagnostic Discussion
Last updated
3 July 2026
Data type
forecast
Limitations
  • This is the official alert status and synopsis, not a structured probability breakdown — IRI/CPC do not publish a clean El Niño/Neutral/La Niña percentage table for free access.
  • The quoted statement (if shown) is whichever specific probability the discussion happened to lead with, not necessarily a full picture across every lead time.
  • Forecast uncertainty increases the further out the period.
Updated 3 July 2026

Atmosphere check

-24.9 Mixed SOI, Jun 2026 (monthly)

−30 (La Niña-like) 0 +30 (El Niño-like)

SOI is -24.9 while ONI is +0.48. These aren't clearly reinforcing each other right now — the atmospheric response is mixed rather than strongly coupled to the ocean signal.

Evidence & limitations
Source
Australian BOM SOI
Last updated
3 July 2026
Data type
observed
Limitations
  • Coupling classification follows the rule validated against real data in docs/methodology.md.
  • SOI is one indicator of atmospheric response; it does not capture the full atmospheric picture.
Updated 3 July 2026

Niño 3.4 trend

+0.48°C latest reading, 2026-MAM

-2 -1 0 +1 +2 2024-AMJ 2024-JJA 2024-ASO 2024-OND 2025-DJF 2025-FMA 2025-AMJ 2025-JJA 2025-ASO 2025-OND 2026-DJF 2026-FMA
Evidence & limitations
Source
NOAA ONI (CPC)
Last updated
3 July 2026
Data type
observed
Limitations
  • Threshold bands are drawn at ±0.5 / ±1.0 / ±1.5 / ±2.0°C per the standard ONI scale.
  • Recent months may be revised as more observations come in.