Was the forecast right for Seattle on Sun Aug 9?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Seattle's Sun Aug 9 high anywhere from 68° to 81°;by the final call, the day before, the field had settled to a median of 78°. The day verified at 76° against the ECMWF IFS analysis — cloudy.
GFS landed closest, off by 1.6°. AIGFS ran 4° warm.
What every model said, at every lead
Daily-high calls for Sun Aug 9 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 · 2026-07-25 | — | 74° | — | — | 81° | — | — | 74–81° |
| 14d · 2026-07-26 | 73° | 68° | 78° | — | 81° | — | — | 68–81° |
| 13d · 2026-07-27 | 73° | 69° | 78° | — | 73° | — | — | 69–78° |
| 12d · 2026-07-28 | 79° | 86° | 73° | — | 86° | — | — | 73–86° |
| 11d · 2026-07-29 | 80° | 92° | 77° | — | 92° | — | — | 77–92° |
| 10d · 2026-07-30 | 68° | 85° | 79° | — | 95° | — | — | 68–95° |
| 9d · 2026-07-31 | 76° | 84° | 88° | 77° | 77° | — | — | 76–88° |
| 8d · 2026-08-01 | 77° | 81° | 79° | 79° | 82° | — | — | 77–82° |
| 7d · 2026-08-02 | 76° | 81° | 73° | 73° | 79° | 76° | — | 73–81° |
| 6d · 2026-08-03 | 79° | 83° | 74° | 74° | 84° | 74° | 77° | 74–84° |
| 5d · 2026-08-04 | 76° | 86° | 78° | 78° | 84° | 77° | 77° | 76–86° |
| 4d · 2026-08-05 | 73° | 85° | 78° | 73° | 83° | 77° | 77° | 73–85° |
| 3d · 2026-08-06 | 74° | 83° | 76° | 75° | 83° | 75° | 76° | 74–83° |
| 2d · 2026-08-07 | 73° | 81° | 77° | 76° | 80° | 75° | 77° | 73–81° |
| 1d · 2026-08-08 | 73° | 80° | 78° | 78° | 77° | 74° | 78° | 73–80° |
| actual | 76° |
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 ECMWF IFS analysis (temperature_2m_max). 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.