The Spread

Was the forecast right for Seattle on Wed Aug 5?

Seattle, Washington · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

14 days out, 4 models put Seattle's Wed Aug 5 high anywhere from 22° to 27°; by the final call the field had settled to a median of 28°. The day verified at 29° against the ECMWF IFS analysis — partly cloudy.

ECMWF landed closest, off by 0.0°. AIGFS ran 3° hot.

14 days out the models said 22–27; it hit 29. ECMWF led (off 0.0°C); AIGFS ran 3°C hot.
The shareable card for this receipt — what this page looks like pasted into a thread.

What every model said, at every lead

Daily-high calls for Wed Aug 5 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 AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-07-21 18° 19° 18–19°
14d · 2026-07-22 27° 22° 26° 27° 22–27°
13d · 2026-07-23 24° 33° 22° 22° 22–33°
12d · 2026-07-24 29° 23° 31° 16° 16–31°
11d · 2026-07-25 26° 27° 25° 28° 25–28°
10d · 2026-07-26 25° 29° 27° 30° 25–30°
9d · 2026-07-27 28° 28° 28° 24° 34° 24–34°
8d · 2026-07-28 23° 36° 18° 24° 32° 18–36°
7d · 2026-07-29 29° 33° 28° 25° 31° 25–33°
6d · 2026-07-30 28° 33° 30° 26° 30° 29° 32° 26–33°
5d · 2026-07-31 28° 32° 29° 26° 29° 26° 29° 26–32°
4d · 2026-08-01 29° 33° 30° 26° 30° 28° 29° 26–33°
3d · 2026-08-02 29° 33° 31° 27° 30° 28° 29° 27–33°
2d · 2026-08-03 29° 33° 30° 26° 30° 28° 29° 26–33°
1d · 2026-08-04 28° 32° 29° 28° 29° 27° 28° 27–32°
0d · 2026-08-05 27° 31° 29° 27° 28° 26° 28° 26–31°
actual 29°

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). Archive depth varies by city; receipts exist only for dates the archive watched arrive.