The Pacific pulse behind global weather
Follow El Niño and La Niña through NOAA’s Relative Oceanic Niño Index—the official three-month measure of changing Pacific sea-surface temperatures.
La Niña
cooler
El Niño
warmer
Warm signal
Observed JAS 2026 · +1.7°C
Official NOAA outlook
Issued October 2026. This is the forward-looking assessment that news reports refer to—not the retrospective episode colouring in the historical RONI table.
SON forecast
100%
chance of El Niño
Peak strength signal: 100% chance of RONI reaching at least +2.0°C in SON.
Next nine overlapping seasons
Event strength does not directly determine the severity of impacts in any particular region.
Ocean temperature, over time
Values above +0.5°C lean warm; below −0.5°C lean cool. NOAA confirms an event only after the pattern persists across five overlapping seasons.
Latest published periods
| Period | Ends | RONI | Historical episode |
|---|---|---|---|
| JAS 2026 | Sep 2026 | +1.7°C | Pending persistence |
| JJA 2026 | Aug 2026 | +1.4°C | Pending persistence |
| MJJ 2026 | Jul 2026 | +1.0°C | Pending persistence |
| AMJ 2026 | Jun 2026 | +0.5°C | Pending persistence |
| MAM 2026 | May 2026 | +0.0°C | No episode |
| FMA 2026 | Apr 2026 | -0.4°C | No episode |
| JFM 2026 | Mar 2026 | -0.8°C | La Niña |
| DJF 2026 | Feb 2026 | -0.9°C | La Niña |
| NDJ 2025 | Jan 2026 | -1.0°C | La Niña |
| OND 2025 | Dec 2025 | -1.0°C | La Niña |
| SON 2025 | Nov 2025 | -0.9°C | La Niña |
| ASO 2025 | Oct 2025 | -0.8°C | La Niña |