Was the forecast right for Seattle on Sun Sep 6?
Seattle, Washington · daily high temperature in °C · forecasts from each model's archived runs, verified against the SEA observations
14 days out, 4 models put Seattle's Sun Sep 6 high anywhere from 17° to 28°;by the final call, the day before, the field had settled to a median of 22°. The day verified at 23° against the SEA observations — cloudy.
UKMO landed closest, off by 0.1°. AIFS ran 3° cool.
What every model said, at every lead
Daily-high calls for Sun Sep 6 as each model's runs approached it — the last archived run per day. NBM and The Spread's own blend are consensus products and stay out of these ranges and rankings; the Seattle scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 14d · 2026-08-23 | 18° | 28° | 17° | — | 24° | — | — | 17–28° |
| 13d · 2026-08-24 | 27° | 30° | 31° | — | 34° | — | — | 27–34° |
| 12d · 2026-08-25 | 27° | 26° | 26° | — | 26° | — | — | 26–27° |
| 11d · 2026-08-26 | 24° | 23° | 19° | — | 28° | — | — | 19–28° |
| 10d · 2026-08-27 | 20° | 26° | 19° | — | 26° | — | — | 19–26° |
| 9d · 2026-08-28 | 18° | 16° | 18° | 20° | 26° | — | — | 16–26° |
| 8d · 2026-08-29 | 19° | 15° | 19° | 21° | 26° | — | — | 15–26° |
| 7d · 2026-08-30 | 18° | 23° | 22° | 20° | 25° | 22° | — | 18–25° |
| 6d · 2026-08-31 | 20° | 20° | 18° | 22° | 27° | 22° | 23° | 18–27° |
| 5d · 2026-09-01 | 19° | 24° | 21° | 21° | 24° | 23° | 24° | 19–24° |
| 4d · 2026-09-02 | 20° | 23° | 21° | 20° | 23° | 21° | 22° | 20–23° |
| 3d · 2026-09-03 | 21° | 23° | 21° | 19° | 24° | 21° | 23° | 19–24° |
| 2d · 2026-09-04 | 21° | 23° | 21° | 22° | 24° | 21° | 23° | 21–24° |
| 1d · 2026-09-05 | 21° | 22° | 21° | 24° | 24° | 21° | 23° | 21–24° |
| actual | 23° |
Read it honestly
This is one date, not a league table. A model can win a day it deserved to lose; rankings only mean something over a window. For that, see which model has been most accurate in Seattle — or every city The Spread scores.
Forecasts are what each model's archived runs said at the time, captured at The Spread's sweep times — never reconstructed after the fact. Truth is the SEA observations. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.