Was the forecast right for Seattle on Fri Sep 4?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the SEA observations
12 days out, 4 models put Seattle's Fri Sep 4 high anywhere from 58° to 68°;by the final call, the day before, the field had settled to a median of 69°. The day verified at 70° against the SEA observations, with 0.01 in of precipitation — drizzle.
GEM landed closest, off by 0.3°. AIFS ran 4° cool.
What every model said, at every lead
Daily-high calls for Fri Sep 4 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 |
|---|---|---|---|---|---|---|---|---|
| 12d · 2026-08-23 | 65° | 68° | 66° | — | 58° | — | — | 58–68° |
| 11d · 2026-08-24 | 72° | 72° | 75° | — | 82° | — | — | 72–82° |
| 10d · 2026-08-25 | 71° | 58° | 70° | — | 68° | — | — | 58–71° |
| 9d · 2026-08-26 | 67° | 65° | 63° | 71° | 71° | — | — | 63–71° |
| 8d · 2026-08-27 | 60° | 64° | 64° | 62° | 68° | — | — | 60–68° |
| 7d · 2026-08-28 | 65° | 65° | 66° | 61° | 72° | 66° | — | 61–72° |
| 6d · 2026-08-29 | 62° | 73° | 65° | 65° | 58° | 64° | 62° | 58–73° |
| 5d · 2026-08-30 | 64° | 66° | 66° | 64° | 70° | 63° | 65° | 63–70° |
| 4d · 2026-08-31 | 62° | 67° | 61° | 67° | 68° | 59° | 68° | 59–68° |
| 3d · 2026-09-01 | 62° | 67° | 67° | 67° | 70° | 67° | 69° | 62–70° |
| 2d · 2026-09-02 | 65° | 67° | 67° | 68° | 69° | 67° | 70° | 65–70° |
| 1d · 2026-09-03 | 66° | 69° | 67° | 70° | 72° | 66° | 71° | 66–72° |
| actual | 70° |
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.