Key Takeaways
- El Niño developing. The weekly Niño-3.4 sea-surface temperature anomaly is +1.5 °C and the official ONI (Mar–May 2026) is +0.48 °C. NOAA has an El Niño Watch in effect.
- A fast Pacific warm-up. Niño-3.4 has climbed from near neutral earlier in 2026 to well above the +0.5 °C El Niño threshold — one of the sharper spring warm-ups in recent years.
- El Niño likely into winter. IRI/CPC probabilities favour El Niño at roughly 80–91% through the 2026–27 winter before easing in early 2027.
- Global ripple effects. El Niño typically brings drier conditions to Australia, Indonesia and southern Africa, wetter weather to Peru, Ecuador and East Africa, and milder winters to Canada and northern Asia.
- Updated weekly. This page refreshes automatically from NOAA CPC data — weekly Niño-3.4 and ONI, plus the monthly IRI/CPC forecast.
El Niño and La Niña — the two phases of the El Niño–Southern Oscillation (ENSO) — are the single biggest driver of year-to-year swings in global weather. They begin as a warming or cooling of the central and eastern equatorial Pacific, then ripple out to shift rainfall, temperature and storm patterns across six continents. This page tracks where ENSO stands right now, updated automatically from NOAA data.
What’s happening now
As of 18 June 2026, the equatorial Pacific is warming: the weekly Niño-3.4 index stands at +1.5 °C — firmly in El Niño territory, while the official three-month ONI for Mar–May 2026 is +0.48 °C. NOAA’s Climate Prediction Center currently has an El Niño Watch in effect. Forecasters give El Niño roughly an 80–90%+ chance of persisting and strengthening through the 2026–27 Northern Hemisphere winter.
Niño-3.4: the index to watch
The headline number for ENSO is the Niño-3.4 sea-surface temperature anomaly — how much warmer or cooler than normal the central equatorial Pacific is. Above +0.5 °C signals El Niño; below −0.5 °C signals La Niña. Here is the weekly trend over the past 18 months.
The official record: the ONI
An official El Niño or La Niña isn’t declared on a single week. NOAA uses the Oceanic Niño Index (ONI) — a three-month running average of Niño-3.4 — and requires it to stay past the ±0.5 °C threshold for five overlapping seasons. The strip below shows every El Niño (red) and La Niña (blue) since 2014.
The Pacific warm tongue
ENSO is monitored across four regions of the equatorial Pacific. During El Niño a band of warmer-than-normal water — the “warm tongue” — stretches from the Date Line toward South America. The map shows the current anomaly in each Niño region.
What’s next: the ENSO forecast
Each month the IRI and NOAA issue probabilities for El Niño, neutral and La Niña over the coming seasons. The current outlook strongly favours El Niño through the 2026–27 winter.
What El Niño means around the world
El Niño reshuffles global weather. It typically brings drought to Australia, Indonesia, the Philippines, India and southern Africa; heavier rain and flooding to coastal Peru and Ecuador, southeastern South America and East Africa; and milder winters to Canada and northern Asia. It also tends to suppress Atlantic hurricane activity while boosting it in the Pacific. La Niña broadly flips these patterns.
How to read this page
All ocean figures come straight from NOAA’s Climate Prediction Center and refresh weekly; the probability forecast updates monthly from the IRI/CPC. ENSO is inherently variable, and a developing event can stall or accelerate — treat the trend and the forecast probabilities, rather than any single weekly value, as the best guide to where things are heading.
Live ocean data from NOAA's Climate Prediction Center; probability forecast from the IRI/CPC. ENSO is the El Niño–Southern Oscillation. This page updates automatically; figures are provisional.
Data Sources:
- NOAA CPC — Weekly ENSO / Niño SST indices – Weekly Niño-region SST anomalies and the ONI.
- NOAA CPC — ENSO Diagnostic Discussion – Official El Niño / La Niña status and alerts.
- IRI / CPC — ENSO probability forecast – Probability of El Niño / Neutral / La Niña by season.
Image Sources:
- Charts & maps by Mappr – Built from NOAA CPC and IRI data.
