Was the forecast right for Seattle on Mon Sep 21?
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 Mon Sep 21 high anywhere from 60° to 78°;by the call made on the day itself the field had settled to a median of 67°. The day verified at 67° against the SEA observations — cloudy.
UKMO landed closest, off by 0.0°. GFS ran 5° warm.
What every model said, at every lead
Daily-high calls for Mon Sep 21 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 · 2026-09-06 | — | 69° | — | — | 83° | — | — | 69–83° |
| 14d · 2026-09-07 | 68° | 66° | 60° | — | 78° | — | — | 60–78° |
| 13d · 2026-09-08 | 58° | 66° | 64° | — | 74° | — | — | 58–74° |
| 12d · 2026-09-09 | 68° | 66° | 70° | — | 74° | — | — | 66–74° |
| 11d · 2026-09-10 | 60° | 62° | 74° | — | 78° | — | — | 60–78° |
| 10d · 2026-09-11 | 64° | 67° | 66° | — | 74° | — | — | 64–74° |
| 9d · 2026-09-12 | 64° | 66° | 64° | 72° | 70° | — | — | 64–72° |
| 8d · 2026-09-13 | 66° | 68° | 71° | 72° | 76° | — | — | 66–76° |
| 7d · 2026-09-14 | 61° | 63° | 66° | 70° | 70° | — | — | 61–70° |
| 6d · 2026-09-15 | 65° | 62° | 67° | 70° | 72° | 67° | 68° | 62–72° |
| 5d · 2026-09-16 | 64° | 71° | 67° | 69° | 74° | 69° | 69° | 64–74° |
| 4d · 2026-09-17 | 64° | 70° | 67° | 68° | 74° | 68° | 69° | 64–74° |
| 3d · 2026-09-18 | 64° | 69° | 69° | 71° | 73° | 69° | 70° | 64–73° |
| 2d · 2026-09-19 | 64° | 69° | 66° | 70° | 74° | 69° | 70° | 64–74° |
| 1d · 2026-09-20 | 64° | 69° | 67° | 68° | 72° | 65° | 66° | 64–72° |
| 0d · 2026-09-21 | 65° | 69° | 67° | 68° | 72° | 63° | 67° | 63–72° |
| actual | 67° |
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.