Was the forecast right for Seattle on Sun Sep 6?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the SEA observations
14 days out, 4 models put Seattle's Sun Sep 6 high anywhere from 63° to 83°;by the final call, the day before, the field had settled to a median of 72°. The day verified at 74° against the SEA observations — cloudy.
UKMO landed closest, off by 0.1°. AIFS ran 5° cool.
What every model said, at every lead
Daily-high calls for Sun Sep 6 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 |
|---|---|---|---|---|---|---|---|---|
| 14d · 2026-08-23 | 65° | 83° | 63° | — | 76° | — | — | 63–83° |
| 13d · 2026-08-24 | 80° | 85° | 89° | — | 92° | — | — | 80–92° |
| 12d · 2026-08-25 | 80° | 78° | 79° | — | 78° | — | — | 78–80° |
| 11d · 2026-08-26 | 75° | 74° | 66° | — | 83° | — | — | 66–83° |
| 10d · 2026-08-27 | 68° | 78° | 66° | — | 79° | — | — | 66–79° |
| 9d · 2026-08-28 | 65° | 60° | 64° | 68° | 78° | — | — | 60–78° |
| 8d · 2026-08-29 | 66° | 58° | 66° | 70° | 78° | — | — | 58–78° |
| 7d · 2026-08-30 | 65° | 73° | 72° | 69° | 78° | 71° | — | 65–78° |
| 6d · 2026-08-31 | 68° | 69° | 64° | 71° | 80° | 71° | 73° | 64–80° |
| 5d · 2026-09-01 | 66° | 74° | 70° | 70° | 76° | 73° | 76° | 66–76° |
| 4d · 2026-09-02 | 67° | 73° | 71° | 69° | 74° | 70° | 71° | 67–74° |
| 3d · 2026-09-03 | 69° | 74° | 70° | 67° | 76° | 69° | 73° | 67–76° |
| 2d · 2026-09-04 | 70° | 73° | 70° | 71° | 75° | 69° | 74° | 69–75° |
| 1d · 2026-09-05 | 69° | 72° | 69° | 75° | 75° | 71° | 74° | 69–75° |
| actual | 74° |
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.