Was the forecast right for Seattle on Tue Sep 1?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the SEA observations
9 days out, 5 models put Seattle's Tue Sep 1 high anywhere from 66° to 72°; by the final call the field had settled to a median of 71°. The day verified at 66° against the SEA observations — drizzle.
AIFS landed closest, off by 0.9°. GFS ran 8° hot.
What every model said, at every lead
Daily-high calls for Tue Sep 1 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 |
|---|---|---|---|---|---|---|---|---|
| 9d · 2026-08-23 | 66° | 72° | 72° | 66° | 72° | — | — | 66–72° |
| 8d · 2026-08-24 | 63° | 67° | 67° | 69° | 71° | — | — | 63–71° |
| 7d · 2026-08-25 | 63° | 63° | 70° | 64° | 71° | — | — | 63–71° |
| 6d · 2026-08-26 | 67° | 71° | 64° | 71° | 68° | 69° | 67° | 64–71° |
| 5d · 2026-08-27 | 70° | 73° | 68° | 71° | 74° | 71° | 66° | 66–74° |
| 4d · 2026-08-28 | 68° | 76° | 71° | 72° | 79° | 72° | 73° | 68–79° |
| 3d · 2026-08-29 | 67° | 72° | 76° | 70° | 79° | 73° | 74° | 67–79° |
| 2d · 2026-08-30 | 67° | 69° | 74° | 70° | 79° | 69° | 73° | 67–79° |
| 1d · 2026-08-31 | 67° | 68° | 72° | 71° | 77° | 69° | 71° | 67–77° |
| 0d · 2026-09-01 | 67° | 68° | 71° | 71° | 74° | 68° | 72° | 67–74° |
| actual | 66° |
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.