Was the forecast right for Seattle on Tue Aug 4?
Seattle, Washington · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Seattle's Tue Aug 4 high anywhere from 76° to 87°;by the final call, the day before, the field had settled to a median of 80°. The day verified at 79° against the ECMWF IFS analysis — clear.
ICON landed closest, off by 0.5°. AIGFS ran 6° warm.
What every model said, at every lead
Daily-high calls for Tue Aug 4 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 · 2026-07-20 | — | 79° | — | — | 78° | — | — | 78–79° |
| 14d · 2026-07-21 | 76° | 81° | 87° | — | 87° | — | — | 76–87° |
| 13d · 2026-07-22 | 79° | 84° | 76° | — | 84° | — | — | 76–84° |
| 12d · 2026-07-23 | 70° | 82° | 79° | — | 89° | — | — | 70–89° |
| 11d · 2026-07-24 | 82° | 84° | 83° | — | 83° | — | — | 82–84° |
| 10d · 2026-07-25 | 80° | 85° | 83° | — | 81° | — | — | 80–85° |
| 9d · 2026-07-26 | 83° | 88° | 80° | 76° | 82° | — | — | 76–88° |
| 8d · 2026-07-27 | 80° | 90° | 77° | 78° | 77° | — | — | 77–90° |
| 7d · 2026-07-28 | 81° | 88° | 77° | 78° | 84° | 78° | — | 77–88° |
| 6d · 2026-07-29 | 82° | 86° | 83° | 77° | 81° | 81° | 82° | 77–86° |
| 5d · 2026-07-30 | 80° | 85° | 82° | 77° | 82° | 81° | 83° | 77–85° |
| 4d · 2026-07-31 | 81° | 86° | 82° | 77° | 83° | 80° | 83° | 77–86° |
| 3d · 2026-08-01 | 81° | 86° | 84° | 77° | 83° | 80° | 82° | 77–86° |
| 2d · 2026-08-02 | 81° | 86° | 83° | 80° | 81° | 80° | 83° | 80–86° |
| 1d · 2026-08-03 | 80° | 86° | 82° | 80° | 80° | 79° | 81° | 79–86° |
| actual | 79° |
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.