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 58° to 66°;by the final call, the day before, 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 3.5°. GEM ran 6° cool.
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 | 64° | 66° | 65° | — | 58° | — | — | 58–66° |
| 10d · 2026-08-24 | 68° | 64° | 69° | — | 77° | — | — | 64–77° |
| 9d · 2026-08-25 | 68° | 65° | 66° | 62° | 57° | — | — | 57–68° |
| 8d · 2026-08-26 | 63° | 58° | 60° | 68° | 56° | — | — | 56–68° |
| 7d · 2026-08-27 | 64° | 59° | 62° | 58° | 67° | 69° | — | 58–69° |
| 6d · 2026-08-28 | 66° | 68° | 67° | 58° | 56° | 60° | 66° | 56–68° |
| 5d · 2026-08-29 | 61° | 72° | 59° | 64° | 73° | 61° | 62° | 59–73° |
| 4d · 2026-08-30 | 61° | 64° | 62° | 63° | 62° | 67° | 60° | 60–67° |
| 3d · 2026-08-31 | 64° | 62° | 65° | 67° | 72° | 65° | 66° | 62–72° |
| 2d · 2026-09-01 | 63° | 62° | 62° | 65° | 67° | 63° | 63° | 62–67° |
| 1d · 2026-09-02 | 62° | 64° | 64° | 62° | 64° | 64° | 64° | 62–64° |
| 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. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.