Was the forecast right for Seattle on Thu Sep 3?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the SEA observations
11 days out, 4 models put Seattle's Thu Sep 3 high anywhere from 61° to 75°; by the final call the field had settled to a median of 64°. The day verified at 68° against the SEA observations, with 0.12 in of precipitation — showers.
GFS landed closest, off by 0.6°. AIFS ran 6° cold.
What every model said, at every lead
Daily-high calls for Thu Sep 3 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 |
|---|---|---|---|---|---|---|---|---|
| 11d · 2026-08-23 | 61° | 62° | 65° | — | 75° | — | — | 61–75° |
| 10d · 2026-08-24 | 64° | 63° | 69° | — | 66° | — | — | 63–69° |
| 9d · 2026-08-25 | 67° | 65° | 66° | 68° | 68° | — | — | 65–68° |
| 8d · 2026-08-26 | 66° | 61° | 60° | 67° | 58° | — | — | 58–67° |
| 7d · 2026-08-27 | 64° | 58° | 62° | 67° | 64° | — | — | 58–67° |
| 6d · 2026-08-28 | 61° | 65° | 67° | 62° | 66° | 62° | 66° | 61–67° |
| 5d · 2026-08-29 | 62° | 72° | 60° | 58° | 72° | 61° | 62° | 58–72° |
| 4d · 2026-08-30 | 63° | 64° | 64° | 62° | 64° | 64° | 60° | 60–64° |
| 3d · 2026-08-31 | 62° | 61° | 63° | 64° | 64° | 64° | 66° | 61–66° |
| 2d · 2026-09-01 | 62° | 62° | 63° | 65° | 71° | 64° | 63° | 62–71° |
| 1d · 2026-09-02 | 62° | 62° | 64° | 64° | 64° | 64° | 64° | 62–64° |
| 0d · 2026-09-03 | 62° | 64° | 64° | 64° | 67° | 63° | 65° | 62–67° |
| 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.