Was the forecast right for Seattle on Tue Sep 15?
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 Tue Sep 15 high anywhere from 62° to 80°; by the final call the field had settled to a median of 66°. The day verified at 68° against the SEA observations, with 0.01 in of precipitation — drizzle.
GEM landed closest, off by 0.1°. AIFS ran 4° cold.
What every model said, at every lead
Daily-high calls for Tue Sep 15 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 · 2026-08-31 | — | 75° | — | — | 80° | — | — | 75–80° |
| 14d · 2026-09-01 | 62° | 74° | 67° | — | 80° | — | — | 62–80° |
| 13d · 2026-09-02 | 73° | 57° | 68° | — | 77° | — | — | 57–77° |
| 12d · 2026-09-03 | 71° | 80° | 71° | — | 64° | — | — | 64–80° |
| 11d · 2026-09-04 | 69° | 76° | 64° | — | 66° | — | — | 64–76° |
| 10d · 2026-09-05 | 76° | 73° | 74° | — | 82° | — | — | 73–82° |
| 9d · 2026-09-06 | 63° | 65° | 70° | 68° | 78° | — | — | 63–78° |
| 8d · 2026-09-07 | 69° | 70° | 71° | 67° | 78° | — | — | 67–78° |
| 7d · 2026-09-08 | 65° | 57° | 72° | 67° | 70° | — | — | 57–72° |
| 6d · 2026-09-09 | 67° | 71° | 71° | 66° | 80° | 68° | 76° | 66–80° |
| 5d · 2026-09-10 | 68° | 71° | 68° | 68° | 74° | 72° | 74° | 68–74° |
| 4d · 2026-09-11 | 67° | 70° | 66° | 67° | 70° | 67° | 70° | 66–70° |
| 3d · 2026-09-12 | 65° | 68° | 63° | 67° | 71° | 67° | 67° | 63–71° |
| 2d · 2026-09-13 | 63° | 65° | 62° | 66° | 69° | 62° | 63° | 62–69° |
| 1d · 2026-09-14 | 63° | 63° | 63° | 68° | 68° | 61° | 64° | 61–68° |
| 0d · 2026-09-15 | 64° | 67° | 64° | 68° | 68° | 64° | 66° | 64–68° |
| actual | 68° |
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.