Was the forecast right for Seattle on Fri Sep 11?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the SEA observations
14 days out, 4 models put Seattle's Fri Sep 11 high anywhere from 60° to 68°;by the final call, the day before, the field had settled to a median of 68°. The day verified at 67° against the SEA observations — drizzle.
ECMWF landed closest, off by 0.7°. GEM ran 3° warm.
What every model said, at every lead
Daily-high calls for Fri Sep 11 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, labeled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-27 | — | 62° | — | — | 84° | — | — | 62–84° |
| 14d · 2026-08-28 | 65° | 60° | 68° | — | 63° | — | — | 60–68° |
| 13d · 2026-08-29 | 70° | 71° | 69° | — | 76° | — | — | 69–76° |
| 12d · 2026-08-30 | 77° | 72° | 72° | — | 83° | — | — | 72–83° |
| 11d · 2026-08-31 | 69° | 76° | 62° | — | 65° | — | — | 62–76° |
| 10d · 2026-09-01 | 67° | 63° | 71° | — | 63° | — | — | 63–71° |
| 9d · 2026-09-02 | 61° | 60° | 71° | 60° | 71° | — | — | 60–71° |
| 8d · 2026-09-03 | 69° | 80° | 61° | 66° | 78° | — | — | 61–80° |
| 7d · 2026-09-04 | 67° | 63° | 70° | 79° | 72° | 71° | — | 63–79° |
| 6d · 2026-09-05 | 64° | 61° | 69° | 69° | 66° | 64° | 67° | 61–69° |
| 5d · 2026-09-06 | 65° | 67° | 66° | 67° | 63° | 66° | 68° | 63–68° |
| 4d · 2026-09-07 | 66° | 70° | 67° | 65° | 66° | 66° | 64° | 64–70° |
| 3d · 2026-09-08 | 65° | 66° | 65° | 65° | 66° | 67° | 66° | 65–67° |
| 2d · 2026-09-09 | 65° | 66° | 66° | 68° | 67° | 66° | 67° | 65–68° |
| 1d · 2026-09-10 | 65° | 68° | 68° | 70° | 69° | 66° | 68° | 65–70° |
| actual | 67° |
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 day was verified, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; verified days exist only for dates the archive watched arrive.