Was the forecast right for Seattle on Thu Sep 17?
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 17 high anywhere from 66° to 77°; by the final call the field had settled to a median of 74°. The day verified at 77° against the SEA observations — partly cloudy.
GFS landed closest, off by 1.0°. AIFS ran 7° cold.
What every model said, at every lead
Daily-high calls for Thu Sep 17 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 · 2026-09-02 | — | 66° | — | — | 87° | — | — | 66–87° |
| 14d · 2026-09-03 | 66° | 72° | 77° | — | 68° | — | — | 66–77° |
| 13d · 2026-09-04 | 68° | 56° | 70° | — | 74° | — | — | 56–74° |
| 12d · 2026-09-05 | 65° | 78° | 71° | — | 66° | — | — | 65–78° |
| 11d · 2026-09-06 | 70° | 78° | 76° | — | 78° | — | — | 70–78° |
| 10d · 2026-09-07 | 78° | 79° | 67° | — | 81° | — | — | 67–81° |
| 9d · 2026-09-08 | 71° | 70° | 67° | 71° | 68° | — | — | 67–71° |
| 8d · 2026-09-09 | 73° | 80° | 82° | 73° | 90° | — | — | 73–90° |
| 7d · 2026-09-10 | 73° | 79° | 76° | 74° | 84° | — | — | 73–84° |
| 6d · 2026-09-11 | 73° | 78° | 73° | 75° | 83° | 78° | 76° | 73–83° |
| 5d · 2026-09-12 | 72° | 78° | 68° | 74° | 82° | 77° | 74° | 68–82° |
| 4d · 2026-09-13 | 72° | 76° | 69° | 72° | 78° | 72° | 73° | 69–78° |
| 3d · 2026-09-14 | 72° | 76° | 70° | 73° | 78° | 71° | 74° | 70–78° |
| 2d · 2026-09-15 | 72° | 76° | 71° | 73° | 78° | 71° | 75° | 71–78° |
| 1d · 2026-09-16 | 72° | 75° | 71° | 75° | 78° | 72° | 74° | 71–78° |
| 0d · 2026-09-17 | 70° | 75° | 70° | 74° | 78° | 71° | 74° | 70–78° |
| actual | 77° |
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.