How to read this
El Niño and US winters · NOAA's odds
- Pick your city or ski area: search, choose from the list, tap a popular location or a dot on the map, or use your location (it stays on your device).
- Read NOAA's outlook for Dec 2026–Feb 2027: the chance that temperature and precipitation end up above, near or below normal.
- Check how strong El Niño is right now, from NOAA's latest ENSO discussion.
- See what happened before: total snowfall at the nearest long-record NOAA station in each of the 9 strong El Niño winters since 1950, as a percentage of normal.
The address bar updates as you choose (for example ?loc=chicago-il), so you can share the result.
How El Niño affects US winters
El Niño is a warming of the tropical Pacific that shifts the jet stream. In a typical El Niño winter the storm track runs farther south, so the southern US tends to be wetter and cooler while the northern tier tends to be milder and drier. That doesn't mean more snow everywhere in the south or less snow everywhere in the north: snow needs both moisture and cold air, and a wetter winter can fall as rain.
For this winter, NOAA's Climate Prediction Center (Sep 17, 2026 outlook) shows a wet signal across the southern and central US and up the Atlantic coast into New England, a weak dry tilt in the interior Northwest and Great Lakes, and above-normal temperatures favored across the interior Northwest and northern tier. NOAA also notes a negative Pacific Decadal Oscillation, which may dampen typical El Niño impacts. Read the full prognostic discussion (opens in a new tab).
How to read NOAA's probabilities
NOAA's seasonal outlook doesn't say how many inches of snow will fall. For each place it gives the chance that the season ends up in the upper, middle or lower third of the 1991–2020 record. With no information, each third has a 33% chance. A map area labeled "40–49% Above normal" means NOAA thinks the upper third is the most likely outcome — but there is still roughly a 50–60% chance it isn't. "Equal chances" means NOAA sees no strong tilt either way, not that the winter will be normal.
How strong is this El Niño?
El Niño Advisory · NOAA's Dec–Feb strength odds
NOAA's status is El Niño Advisory (issued Oct 8, 2026): “El Niño continues to strengthen, with a strong-to-very strong El Niño likely through January-March 2027 (remaining greater than an 83% chance).” The latest 3-month values (JAS 2026) are RONI +1.69 °C and ONI +2.16 °C; the weekly Niño-3.4 anomaly for the week of Sep 30, 2026 was +3.2 °C. NOAA puts the chance that October–December 2026 beats every event since 1950 (RONI ≥ +2.5 °C) at 83%.
| Strength (RONI) | Chance |
|---|---|
| Very strong (≥ +2.0 °C) | 81% |
| Strong (+1.5 to +2.0 °C) | 16% |
| Moderate (+1.0 to +1.5 °C) | 3% |
| Weak (+0.5 to +1.0 °C) | 0% |
| Neutral or La Niña | 0% |
Strength isn't destiny. NOAA stresses that a stronger El Niño raises the odds of typical impacts but never guarantees them.
How we count snow
The 9 strong El Niño winters · normals · % of normal
We treat a winter as a strong El Niño winter if its peak 3-month index between Jun–Aug and Feb–Apr reached +1.5 °C or more by either ONI or RONI. That gives 9 winters since 1950: 1957-58, 1965-66, 1972-73, 1982-83, 1991-92, 1997-98, 2009-10, 2015-16, 2023-24. The “Big Three” (1982-83, 1997-98, 2015-16) are NOAA's own term for the strongest events.
- Season total = sum of monthly snowfall from July through June. A trace counts as zero.
- Valid season: every month from October through April must have a monthly total with no more than 3 missing days. If not, the winter shows “No data”.
- Normal = NOAA's 1991–2020 snowfall normal for the station. If NOAA has none, we use the average of at least 15 complete seasons from 1991-92 to 2020-21 and say so.
- % of normal = season total ÷ normal × 100, rounded. Hidden if normal is under 1 inch or fewer than 5 winters are valid.
- Map dots: filled when a place got above-normal snow in at least half of its valid strong El Niño winters, hollow when it did in fewer than half, dashed when snow is rare there or too few winters are complete.
Example: New York (Central Park). normal 29.8 in. In 1997-98 the park got 5.5 in (18% of normal); in 2015-16 it got 32.8 in (110%). Overall it was above normal in 3 of 9 strong El Niño winters, median 72%.
Full details, the station list and our update log are on the method & sources page.
Location pages
71 cities · 20 ski areas
Locations with enough snow (normal of 5+ inches) and complete records for at least 6 of the 9 winters have their own page. Places where snow is rare are still in the picker above.
Frequently asked questions
8 questions
Is El Niño good for snow where I live?
It depends on the region, and even then it is a tilt in the odds, not a promise. In NOAA's Dec–Feb 2026-27 outlook the wet signal covers the southern and central US and runs up the Atlantic coast into New England, while the interior Northwest and Great Lakes lean slightly dry and the northern tier leans warm. Snowfall in past strong El Niño winters also varied widely, even at a single station, so don't assume a regional rule applies to you. Pick your location above to see its own numbers.
What does “equal chances” mean in NOAA's outlook?
Equal chances (EC) means NOAA's Climate Prediction Center sees no strong tilt toward above-, near- or below-normal for that spot this season, so each outcome keeps its usual one-in-three chance. It does not mean “normal weather.” A label like “40–49% chance Above normal” means the above-normal outcome is favored, but below- or near-normal are still quite possible.
What's the difference between ONI and RONI?
Both track sea-surface temperature in the Niño-3.4 region of the Pacific. The traditional Oceanic Niño Index (ONI) compares it with a fixed average; the Relative ONI (RONI) subtracts the warming of the whole tropics, so it isn't inflated by global ocean warming. NOAA now uses RONI to judge El Niño strength. The latest values (JAS 2026) are ONI +2.16 °C and RONI +1.69 °C. The two can disagree about past winters: 2023-24 peaked at ONI 1.99 but RONI 1.42.
Is this the strongest El Niño ever?
Not yet, but it could be. The strongest 3-month RONI since 1950 is about +2.4 °C (1982-83). In its Oct 8, 2026 discussion, NOAA gave a 83% chance that October–December 2026 reaches +2.5 °C or more, which would beat every event since 1950. NOAA's strength table gives a 81% chance of a “very strong” (RONI ≥ +2.0 °C) event in Dec–Feb. A stronger El Niño makes typical impacts more likely, but NOAA notes it never guarantees them.
Why doesn't my ski area's number match the resort's snow report?
We use the nearest NOAA cooperative weather station with a long record (back to 1983 or earlier and still reporting), usually in a town or valley near the resort. Resorts measure at mid-mountain or summit plots that often get far more snow. Use our numbers to compare winters with each other at the same station, not as resort totals.
When does NOAA update the winter outlook?
The current Dec–Feb outlook was issued Sep 17, 2026. NOAA's Climate Prediction Center issues new seasonal outlooks on the third Thursday of each month — the next is Oct 15, 2026, then about Nov 19 and Dec 17 (those two dates are not yet confirmed on NOAA's schedule page). The monthly ENSO discussion comes out on the second Thursday; the next is Nov 12, 2026. We refresh this page after each release.
Is this a snow forecast?
No. It combines NOAA's probability outlook with what actually happened in past strong El Niño winters. Neither tells you how much snow will fall this winter. For forecasts and warnings, use weather.gov or your local National Weather Service office.
Why do some winters say “No data”?
We only count a winter if every month from October through April has a monthly snowfall total with no more than 3 missing days. Otherwise that winter shows “No data” instead of a misleading low total. We also hide percentages when fewer than 5 winters qualify, or when normal snowfall is under 1 inch.
Sources
NOAA CPC · NOAA Regional Climate Centers (ACIS)
El Niño status and synopsis
Issued Oct 8, 2026
El Niño strength chances
Issued October 2026
Dec–Feb temperature and precipitation outlook
Issued Sep 17, 2026
Traditional El Niño index
NOAA's strength index
Station snowfall and 1991–2020 normals
Not a forecast
This is not a weather forecast. Seasonal outlooks are probabilities from NOAA's Climate Prediction Center; past El Niño winters show what happened, not what will happen. Snowfall is from NOAA station records (ACIS) and may contain gaps or station changes. For forecasts and warnings, use weather.gov. Not affiliated with NOAA/NWS.
Last updated: . See the changelog.