Was the forecast right for Seattle on Tue Jul 21?
Seattle, Washington · daily high temperature · forecasts from each model's archived runs, verified against ERA5
4 days out, 7 models put Seattle's Tue Jul 21 high anywhere from 80° to 90°; by the final call the field had settled to a median of 87°. ERA5 says the day verified at 89° — cloudy.
GEM landed closest, off by 0.7°. ICON ran 6° cold.
What every model said, at every lead
Daily-high calls for Tue Jul 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 |
|---|---|---|---|---|---|---|---|---|
| 4d · 2026-07-17 | 84° | 90° | 87° | 81° | 89° | 80° | 88° | 80–90° |
| 3d · 2026-07-18 | 85° | 88° | 86° | 77° | 89° | 76° | 88° | 76–89° |
| 2d · 2026-07-19 | 85° | 88° | 89° | 77° | 89° | 82° | 88° | 77–89° |
| 1d · 2026-07-20 | 86° | 91° | 89° | 88° | 88° | 84° | 88° | 84–91° |
| 0d · 2026-07-21 | 85° | 94° | 88° | 88° | 87° | 84° | 87° | 84–94° |
| actual | 89° |
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 ERA5 reanalysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.