Was the forecast right for Seattle on Mon Jul 20?
Seattle, Washington · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
3 days out, 7 models put Seattle's Mon Jul 20 high anywhere from 23° to 30°;by the final call, the day before, the field had settled to a median of 28°. The day verified at 26° against the ECMWF IFS analysis — cloudy.
AIFS landed closest, off by 0.1°. GFS ran 3° warm.
What every model said, at every lead
Daily-high calls for Mon Jul 20 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 |
|---|---|---|---|---|---|---|---|---|
| 3d · 2026-07-17 | 26° | 30° | 27° | 23° | 29° | 24° | 27° | 23–30° |
| 2d · 2026-07-18 | 26° | 29° | 27° | 26° | 29° | 25° | 27° | 25–29° |
| 1d · 2026-07-19 | 26° | 28° | 28° | 28° | 29° | 25° | 27° | 25–29° |
| actual | 26° |
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.