2026/2027 US Winter Forecast: What a Very Strong El Niño Means

NOAA has an El Niño Advisory in force, and its own forecasters put an 81% chance on the event reaching the “very strong” tier between October and December. If that happens, the 2026/27 winter will be shaped by one of the largest El Niño events in the record going back to 1950.

That is a real signal, and it is worth being precise about what it does and does not tell you. It tilts the odds across whole regions over three months. It does not tell you whether it will snow at your house in January.

What is the 2026/2027 US winter forecast?

Wetter than normal across the southern tier, drier from the Pacific Northwest through the northern Plains and Great Lakes, and milder than normal over most of the country apart from the south — a textbook El Niño winter, and a sharp reversal of last year.

That table summarises the Climate Prediction Center’s own long-lead discussion for the seasons running into winter 2026-27. The forecaster’s wording is that El Niño teleconnections “ramp up through the fall 2026 and winter 2026-2027”, with below-normal precipitation over the Northwest and north-central states “juxtaposed with above-normal precipitation over the southern tier, with highest probabilities over parts of the Southeast in winter 2026-2027 when teleconnections are strongest”.

One nuance worth keeping: a strong El Niño would normally also push the Gulf States drier in places, but CPC has left parts of that region at equal chances, because the dynamical models disagree and the recent decadal trend runs the other way.

Is it El Niño or La Niña this winter?

El Niño, and a fast-strengthening one. The Pacific flipped from a weak La Niña to a strong El Niño in about six months.

Chart: NOAA’s Oceanic Niño Index, the three-month running mean of Niño-3.4 sea surface temperature anomalies. Only completed seasons are plotted.

This matters because a lot of coverage still circulating online describes the coming winter as a La Niña winter. It is not. Here is the index, season by season through 2026:

NOAA’s 9 July diagnostic discussion put the latest weekly Niño-3.4 reading at +1.2 °C, with the far-eastern Niño-1+2 region at +2.7 °C, and described a downwelling Kelvin wave deepening the thermocline. The SST consolidation forecast reaches just under +2.5 °C by late autumn.

The probabilities NOAA attaches: a 97% chance El Niño persists through early spring 2027, an 81% chance it is very strong during October to December, and 75% for November to January.

What did past strong El Niño winters actually do?

All seven of the strongest El Niño winters since 1950 were wetter than the US average. Only five of the seven were warmer — and two were among the coldest fifteen winters in the record.

Chart: NOAA nClimDiv contiguous-US December-February average temperature. The marked winters are those whose Oceanic Niño Index peaked at +1.6 °C or higher.

We pulled NOAA’s national temperature and precipitation series for every winter since 1950 and looked at what the strong El Niño years actually delivered, rather than at what the composite maps say they should. The two right-hand columns are that winter’s rank out of 77, warmest and wettest first:

Two things fall out of that table.

The precipitation signal is the reliable one. Every single strong El Niño winter came in above the 1950-2026 average of 6.80 inches — although 1965-66 only just, by six hundredths of an inch. Two of them, 1997-98 and 1982-83, are the second and third wettest winters in the entire record.

The temperature signal is much weaker than its reputation. The five warm ones are all from 1982-83 onwards; the two cold ones are both from before 1975. That pattern is entangled with the warming trend running through the whole series, so “El Niño means a mild winter” is doing less work than it appears to. 1972-73 had a stronger El Niño than 1982-83 and was 4.3 °F colder.

For context on what you are comparing against, last winter — a weak La Niña — was the second warmest DJF on record at 37.11 °F and the fourth driest at 5.01 inches. The summer that followed it produced the July heat wave that ran across most of the eastern United States and an extreme heat watch across the Mid-South , so the ground the coming winter starts from is warm and, in much of the west, dry.

Will it snow more or less this winter?

More in the southern mountains and the southern tier, probably less in the Pacific Northwest and northern Rockies — but a seasonal outlook cannot tell you about any individual storm.

The physical mechanism is the jet stream. A strong El Niño tends to pull the subtropical jet north and east across the southern United States, which is why the Southeast, the Gulf Coast, southern California and the Southwest get the wet signal. The northern storm track weakens, which is why the Pacific Northwest and northern Rockies get the dry one.

For snow specifically, three cautions apply:

• Wetter does not always mean snowier. The southern tier is wetter under El Niño partly because it is milder, and a milder storm delivers rain where a colder one delivers snow.
• The big snow events do not come from the seasonal signal. A single blocking pattern or a stratospheric warming can deliver a month’s snow in three days, and none of that is predictable in August.
• Regional averages hide the extremes. 1982-83 was the third wettest US winter on record and it was also 2.1 °F warmer than average nationally.

When will we know more?

Three dates. NOAA’s monthly ENSO discussion on 13 August, the next long-lead seasonal outlook on 20 August, and NOAA’s headline Winter Outlook in the autumn.

It is worth being clear about what has and has not been published, because a lot of “NOAA’s winter forecast is out” coverage conflates them:

What exists today is the seasonal outlook set issued in mid-July, which runs out to twelve months and therefore already covers December to February. That is a genuine NOAA product and it is what this article uses. It is not the flagship Winter Outlook, which historically lands in October with the regional maps most people have seen.

Three things could still move the picture: whether the event peaks near +2.5 °C or falls short, how the Madden-Julian Oscillation behaves through the winter, and whether the polar vortex holds. None of the three is settled in August, and the last two are essentially unpredictable at this range.

The bottom line

The 2026/27 US winter will be an El Niño winter, very likely a strong one, and NOAA gives it a real chance of ranking among the biggest events since 1950. The official tilt is wetter across the south with the Southeast most strongly favoured, drier across the Northwest and the northern tier, and milder over most of the country outside the southern states.

The historical record supports the wet part more firmly than the mild part. Every strong El Niño winter since 1950 was wetter than average; two of them were among the coldest in the record. If you want one sentence to carry through to December: El Niño reliably moves the storm track, and much less reliably moves the thermometer.

Seasonal outlooks are probabilistic statements about three-month averages over large regions. They are not forecasts of individual storms, snowfall totals or conditions on any given date. For decisions that depend on actual weather, use your local National Weather Service forecast office.