The Spread

Was the forecast right for Seattle on Sat Aug 15?

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 Sat Aug 15 high anywhere from 19° to 27°; by the final call the field had settled to a median of 24°. The ECMWF IFS analysis says the day verified at 25° with 0.3 mm of precipitation — drizzle.

GEM landed closest, off by 0.6°. AIFS ran 4° cold.

14 days out the models said 19–27; it hit 25. GEM led (off 0.6°C); AIFS ran 4°C cold.
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 Sat Aug 15 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 · 2026-07-31 25° 28° 25–28°
14d · 2026-08-01 27° 19° 24° 24° 19–27°
13d · 2026-08-02 26° 33° 22° 24° 22–33°
12d · 2026-08-03 24° 33° 27° 24° 24–33°
11d · 2026-08-04 25° 31° 30° 27° 25–31°
10d · 2026-08-05 27° 21° 31° 29° 21–31°
9d · 2026-08-06 26° 26° 24° 28° 25° 24–28°
8d · 2026-08-07 24° 25° 29° 24° 29° 24–29°
7d · 2026-08-08 24° 24° 28° 24° 32° 24–32°
6d · 2026-08-09 23° 26° 28° 26° 31° 23° 27° 23–31°
5d · 2026-08-10 22° 26° 27° 24° 30° 26° 26° 22–30°
4d · 2026-08-11 23° 26° 27° 25° 30° 25° 26° 23–30°
3d · 2026-08-12 23° 26° 27° 24° 31° 24° 27° 23–31°
2d · 2026-08-13 22° 26° 27° 24° 30° 25° 26° 22–30°
1d · 2026-08-14 21° 25° 27° 26° 24° 24° 26° 21–27°
0d · 2026-08-15 21° 24° 27° 24° 23° 21° 24° 21–27°
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 the ECMWF IFS analysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.