Why we built Nino34
Nino34 is a live, independent tracker for ENSO — the El Nino/La Nina cycle — built around one simple goal: keep showing the real numbers, sourced and dated, in plain language, without collapsing them into a scarier or simpler story than the data supports. The dashboard pulls directly from NOAA's Climate Prediction Center (CPC) and IRI, shows both ONI and RONI side by side, and tries to stay useful whether you're a longtime ENSO-watcher or you just heard "El Nino" on the news and want to know what it means for your winter.
The gap we're trying to fill
For years, the best plain-language ENSO explainer on the internet was climate.gov's ENSO Blog — NOAA's own team translating CPC's technical monitoring into something a general reader could actually follow. That team was eliminated in May 2025, and climate.gov's public ENSO pages have been left in a pre-Advisory state since, without the kind of active monthly narration the blog used to provide. We want to say this plainly and without any gloating: it's a real loss, and the people who wrote that blog did good, careful work.
What didn't go away is the actual data. NOAA's underlying CPC data products — the ONI and RONI tables, the monthly ENSO Diagnostic Discussion, the seasonal probability outlooks — are still published on their normal schedule. That's the real source of truth, and it's what this entire site is built on. Nino34 exists to keep translating that ongoing, still-flowing data into plain language, the way the ENSO Blog used to, while pointing back to CPC's own products at every turn rather than trying to replace them.
To be unambiguous: Nino34 is independent and educational. It is not an official NOAA product, and it is not affiliated with NOAA, the Climate Prediction Center, or IRI. Every figure on this site traces back to a public NOAA/CPC or IRI data product, and for official forecasts, watches, and advisories, the right place is always CPC's ENSO Diagnostic Discussion directly.
What we commit to, every page
A few editorial rules apply everywhere on this site, not just where it's convenient:
- Every number carries a real "data as of" timestamp. If you see a figure, you can see exactly when it was pulled from its source — not just when the page happened to render.
- Staleness is shown on the page, not hidden. If a source runs past its normal update window, we say so, right where the number lives, instead of quietly leaving old data looking current.
- Probability distributions are shown in full. CPC's seasonal outlook is a spread across categories, not one number. We show the whole spread rather than collapsing it into a single headline percentage that flattens the real uncertainty.
- No city-level "Critical" risk labels are ever assigned from index values alone. An ONI or RONI reading is a large-scale climate signal, not a local risk assessment, and we don't dress it up as one.
For the full technical detail behind these rules — classification thresholds, analog-comparison methodology, regional confidence tiers, and exactly how staleness handling works — see Methodology. For the complete list of data sources and how often each one updates, see Sources.
Part of a small, independent family
Nino34 has a sibling site: HurriTrack, which tracks the Atlantic hurricane season live. Both sites share the same approach — independent, sourced, no fear-mongering, no manufactured urgency — applied to different parts of the same broader weather picture. When El Nino's Atlantic wind shear is quieting the hurricane season, as covered on our hurricane season page, HurriTrack is where you'd go the moment an actual storm needs watching.