Was the forecast right for Seattle on Sun Sep 13?
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 13 high anywhere from 15° to 23°; by the final call the field had settled to a median of 15°. The day verified at 16° against the SEA observations, with 14.0 mm of precipitation — showers.
ECMWF landed closest, off by 0.1°. AIGFS ran 2° cold.
What every model said, at every lead
Daily-high calls for Sun Sep 13 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-29 | — | 24° | — | — | 25° | — | — | 24–25° |
| 14d · 2026-08-30 | 21° | 15° | 19° | — | 23° | — | — | 15–23° |
| 13d · 2026-08-31 | 20° | 15° | 20° | — | 19° | — | — | 15–20° |
| 12d · 2026-09-01 | 20° | 22° | 17° | — | 29° | — | — | 17–29° |
| 11d · 2026-09-02 | 19° | 14° | 26° | — | 25° | — | — | 14–26° |
| 10d · 2026-09-03 | 20° | 23° | 19° | — | 21° | — | — | 19–23° |
| 9d · 2026-09-04 | 21° | 21° | 15° | 21° | 22° | — | — | 15–22° |
| 8d · 2026-09-05 | 20° | 21° | 24° | 23° | 27° | — | — | 20–27° |
| 7d · 2026-09-06 | 15° | 21° | 21° | 20° | 23° | — | — | 15–23° |
| 6d · 2026-09-07 | 17° | 15° | 20° | 16° | 25° | 21° | 22° | 15–25° |
| 5d · 2026-09-08 | 18° | 14° | 20° | 19° | 24° | 19° | 22° | 14–24° |
| 4d · 2026-09-09 | 14° | 15° | 20° | 16° | 20° | 17° | 21° | 14–21° |
| 3d · 2026-09-10 | 17° | 14° | 20° | 21° | 19° | 20° | 23° | 14–23° |
| 2d · 2026-09-11 | 15° | 14° | 17° | 16° | 20° | 16° | 20° | 14–20° |
| 1d · 2026-09-12 | 15° | 13° | 16° | 16° | 14° | 16° | 18° | 13–18° |
| 0d · 2026-09-13 | 15° | 13° | 15° | 16° | 14° | 15° | 16° | 13–16° |
| actual | 16° |
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. Archive depth varies by city; receipts exist only for dates the archive watched arrive.