The Spread

Was the forecast right for Seattle on Wed Aug 12?

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 Wed Aug 12 high anywhere from 25° to 31°; by the final call the field had settled to a median of 24°. ERA5 says the day verified at 24° — partly cloudy.

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

14 days out the models said 25–31; it hit 24. UKMO 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 Wed Aug 12 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 · 2026-07-28 27° 28° 27–28°
14d · 2026-07-29 25° 26° 26° 31° 25–31°
13d · 2026-07-30 18° 26° 24° 26° 18–26°
12d · 2026-07-31 26° 24° 23° 20° 20–26°
11d · 2026-08-01 22° 29° 27° 27° 22–29°
10d · 2026-08-02 20° 29° 26° 30° 20–30°
9d · 2026-08-03 25° 25° 23° 25° 27° 23–27°
8d · 2026-08-04 25° 28° 25° 26° 31° 25–31°
7d · 2026-08-05 21° 22° 24° 23° 26° 21–26°
6d · 2026-08-06 24° 20° 26° 25° 27° 24° 26° 20–27°
5d · 2026-08-07 24° 20° 25° 25° 24° 22° 22° 20–25°
4d · 2026-08-08 23° 21° 25° 24° 28° 25° 22° 21–28°
3d · 2026-08-09 24° 26° 25° 21° 27° 24° 24° 21–27°
2d · 2026-08-10 23° 24° 24° 22° 28° 24° 24° 22–28°
1d · 2026-08-11 23° 25° 24° 25° 24° 23° 25° 23–25°
0d · 2026-08-12 23° 26° 24° 25° 24° 23° 24° 23–26°
actual 24°

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.