The Spread

Was the forecast right for Seattle on Tue Aug 11?

Seattle, Washington · daily high temperature in °C · forecasts from each model's archived runs, verified against ERA5

14 days out, 4 models put Seattle's Tue Aug 11 high anywhere from 21° to 24°; by the final call the field had settled to a median of 25°. ERA5 says the day verified at 25° — cloudy.

GEM landed closest, off by 0.1°. AIGFS ran 2° hot.

14 days out the models said 21–24; it hit 25. GEM led (off 0.1°C); AIGFS ran 2°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 Tue Aug 11 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 · 2026-07-27 25° 26° 25–26°
14d · 2026-07-28 21° 24° 22° 24° 21–24°
13d · 2026-07-29 27° 22° 25° 28° 22–28°
12d · 2026-07-30 18° 32° 28° 22° 18–32°
11d · 2026-07-31 25° 24° 24° 28° 24–28°
10d · 2026-08-01 26° 27° 25° 28° 25–28°
9d · 2026-08-02 23° 27° 26° 25° 31° 23–31°
8d · 2026-08-03 27° 29° 26° 25° 31° 25–31°
7d · 2026-08-04 26° 27° 23° 25° 28° 23–28°
6d · 2026-08-05 21° 26° 26° 24° 29° 22° 26° 21–29°
5d · 2026-08-06 24° 27° 26° 24° 30° 25° 25° 24–30°
4d · 2026-08-07 23° 27° 26° 25° 30° 25° 25° 23–30°
3d · 2026-08-08 24° 28° 26° 23° 28° 24° 25° 23–28°
2d · 2026-08-09 24° 28° 26° 23° 29° 24° 25° 23–29°
1d · 2026-08-10 24° 26° 25° 25° 25° 24° 25° 24–26°
0d · 2026-08-11 23° 27° 25° 25° 24° 24° 25° 23–27°
actual 25°

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.