Was the forecast right for Seattle on Thu Aug 27?
Seattle, Washington · daily high temperature in °C · forecasts from each model's archived runs, verified against the SEA observations
4 days out, 7 models put Seattle's Thu Aug 27 high anywhere from 21° to 25°;by the final call, the day before, the field had settled to a median of 22°. The day verified at 23° against the SEA observations — drizzle.
GEM landed closest, off by 0.2°. AIFS ran 2° cool.
What every model said, at every lead
Daily-high calls for Thu Aug 27 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 |
|---|---|---|---|---|---|---|---|---|
| 4d · 2026-08-23 | 21° | 22° | 23° | 21° | 25° | 21° | 23° | 21–25° |
| 3d · 2026-08-24 | 20° | 22° | 24° | 22° | 25° | 23° | 23° | 20–25° |
| 2d · 2026-08-25 | 20° | 22° | 23° | 24° | 26° | 22° | 23° | 20–26° |
| 1d · 2026-08-26 | 21° | 22° | 22° | 24° | 24° | 22° | 23° | 21–24° |
| actual | 23° |
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.