About El Niño Today
El Niño Today (originally El Niño Hoje, in Portuguese) started with a simple question: can you follow the climate pattern that shapes rain and snow across the Americas without digging through technical bulletins? We take the official Pacific Ocean data and explain what it says in plain language. Every number comes with its source and date.
We are independent and not affiliated with NOAA or any weather service or government, and we do not replace official alerts. For warnings, check your national weather service.
Where the data comes from
| Indicator | Source | Updated at source |
|---|---|---|
| Niño 1+2, 3, 3.4 and 4 (weekly) | NOAA Climate Prediction Center | Weekly (Mondays) |
| ONI (Oceanic Niño Index) | NOAA Climate Prediction Center | Monthly |
| RONI (Relative ONI) | NOAA Climate Prediction Center | Monthly |
| Official alert and probabilities | NOAA monthly ENSO discussion | 2nd Thursday of the month |
How the site updates
Twice a day, an automated job checks NOAA's public data files. If there is new data, the site updates itself; if the source is down, the last valid values stay up.
That is why the date at the top is not always today. NOAA publishes the weekly number a few days after the week it measures, so "week of Nov 4" means that is the latest figure it has released.
How we read the indices
- El Niño: ONI of +0.5 °C or more for several overlapping seasons in a row.
- Strength: we follow NOAA's RONI scale (weak from 0.5; moderate from 1.0; strong from 1.5; very strong from 2.0 °C).
- Impacts: we describe what usually happens in El Niño years, not forecasts for a specific place or date.
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