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SEASON90Forecast SeasonSeasonal Outlooks · U.S. · Europe · Global
Forecast Season/The Analog Bench
Route 09 · Analogs & post-processing

The Analog Bench

Every other route on this site renders somebody else's model. This one makes a forecast of its own, out of the only thing that has ever actually verified: what happened the last time the ocean looked like this. Eighty-six years of candidates, and a scoreboard that says where it works.

SEASON90

Library

86 years
1940–2025, every one of them a candidate

Ocean state

+1.28 °C
Niño-3.4, May–June–July 2026, observed

Skill

0.47 ACC
cross-validated, first season, global

Frames

175
5 layers × 7 views × 5 seasons

Where the ocean is now

observed, not forecast

The predictor is the observed sea-surface temperature pattern over the last three complete months — the ocean is the season's memory, because the atmosphere forgets in a fortnight and the upper ocean does not.

Observed Niño-3.4, monthly, vs 1991–2020 — 2025-07 to 2026-07
07-0.3808-0.3409-0.5510-0.8211-0.9412-0.9601-0.9102-0.5003-0.2604+0.3905+0.8206+1.2807+1.74

The closest years

ranked by pattern correlation · May–June–July 2026

Ranked by how closely each year's global sea-surface anomaly pattern resembles this one, after removing the warming trend from both — without that step the nearest analog to any recent year is simply another recent year, which is a true statement about the trend and a useless one about the season.

YearPattern correlationIts Niño-3.4Similarity
1982+0.48+0.29
2015+0.45+1.16
1957+0.44+0.67
1997+0.41+1.03
1972+0.37+0.24
1992+0.37+0.51
1965+0.36+0.25
1948+0.33-0.07
1993+0.31+0.50
1940+0.28+0.71
1976+0.27-0.39
1941+0.27+0.84

The forecast

5 layers · 7 views · 5 seasons
Layer
View
Season

The constructed-analog composite: what the seasons that followed the closest historical sea-surface states actually did, projected onto this year. Stippled where the method cannot beat chance.

The scoreboard

leave-one-out, 1940–2025

For every year in the record the engine was rebuilt with that year withheld and asked to forecast it. The numbers are anomaly correlation, global first and land second, with the trend removed from both sides — so this is skill at the season, not credit for knowing that the world has warmed since 1940.

Temperature

SeasonConstructedTop-10 by correlationTop-10 by RMSD
ASO 20260.475 0.346 land0.246 0.1110.315 0.199
SON 20260.434 0.307 land0.225 0.1140.283 0.158
OND 20260.385 0.240 land0.201 0.0850.256 0.129
NDJ 20270.355 0.197 land0.188 0.0620.231 0.102
DJF 20270.331 0.185 land0.181 0.0710.217 0.104

Rainfall

SeasonConstructedTop-10 by correlationTop-10 by RMSD
ASO 20260.203 0.196 land0.095 0.0960.073 0.070
SON 20260.189 0.168 land0.088 0.0710.062 0.047
OND 20260.177 0.146 land0.084 0.0500.059 0.022
NDJ 20270.162 0.137 land0.068 0.0130.046 0.004
DJF 20270.155 0.118 land0.059 -0.0150.037 -0.018

Anything below 0.18 is not significantly different from chance at 95 % with this many years, and is stippled out on the world maps above.

How to read this

Four things it is not

Method

The best forecast names no years

The year list and the map are made by different methods, and the scoreboard says so. The named years are the twelve closest patterns — the part worth reading, because you can go and look them up. The map is a constructed analog: a signed least-squares combination of all eighty-six years at once, which scores roughly twice as well and names nobody. Showing only the first would be friendlier; showing only the second would be honest but unreadable.

Trend

Two maps, and the gap between them

The anomaly layer is measured against 1991–2020 and includes the warming trend; the signal layer has that trend taken back out. The difference between them is not a rounding error — over most of the world the trend is the larger half of the anomaly, and a seasonal map that quietly folds the two together is mostly reporting the climate, not the season.

Rainfall

Mostly, we cannot

Seasonal rainfall analog skill is low almost everywhere outside the tropics, and the scoreboard shows it: a fifth of the temperature figure, and below significance over most land. The rainfall maps are published because that is worth seeing, not because they are actionable. Read the skill layer first.

Analogs

No two seasons are the same

A pattern correlation of +0.48 is a good analog by the standards of this record and still leaves three-quarters of the variance unexplained. The ocean repeats itself loosely, the atmosphere over it does not repeat at all, and the ice, the land and the stratosphere are all in different places than they were in 1982. An analog is an argument, not a precedent.