Was the forecast right for Seattle on Thu Sep 10?
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 Thu Sep 10 high anywhere from 67° to 86°;by the final call, the day before, the field had settled to a median of 69°. The day verified at 71° against the SEA observations — cloudy.
GFS landed closest, off by 0.7°. AIFS ran 4° cool.
What every model said, at every lead
Daily-high calls for Thu Sep 10 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 · 2026-08-26 | — | 84° | — | — | 86° | — | — | 84–86° |
| 14d · 2026-08-27 | 68° | 67° | 71° | — | 86° | — | — | 67–86° |
| 13d · 2026-08-28 | 64° | 65° | 66° | — | 64° | — | — | 64–66° |
| 12d · 2026-08-29 | 65° | 65° | 68° | — | 73° | — | — | 65–73° |
| 11d · 2026-08-30 | 72° | 72° | 70° | — | 81° | — | — | 70–81° |
| 10d · 2026-08-31 | 73° | 80° | 66° | — | 62° | — | — | 62–80° |
| 9d · 2026-09-01 | 65° | 64° | 76° | 76° | 76° | — | — | 64–76° |
| 8d · 2026-09-02 | 64° | 63° | 70° | 64° | 77° | — | — | 63–77° |
| 7d · 2026-09-03 | 74° | 80° | 72° | 73° | 87° | 64° | — | 64–87° |
| 6d · 2026-09-04 | 72° | 76° | 68° | 80° | 66° | 72° | 82° | 66–82° |
| 5d · 2026-09-05 | 67° | 81° | 67° | 70° | 81° | 71° | 78° | 67–81° |
| 4d · 2026-09-06 | 66° | 72° | 67° | 69° | 75° | 70° | 70° | 66–75° |
| 3d · 2026-09-07 | 66° | 69° | 65° | 68° | 70° | 67° | 70° | 65–70° |
| 2d · 2026-09-08 | 66° | 68° | 67° | 70° | 68° | 68° | 69° | 66–70° |
| 1d · 2026-09-09 | 67° | 70° | 67° | 73° | 70° | 68° | 69° | 67–73° |
| actual | 71° |
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.