The Spread

Was the forecast right for Seattle on Sat Aug 1?

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 1 high anywhere from 22° to 28°; by the final call the field had settled to a median of 22°. The day verified at 23° against the ECMWF IFS analysis, with 1.0 mm of precipitation — drizzle.

GEM landed closest, off by 0.4°. AIFS ran 2° cold.

14 days out the models said 22–28; it hit 23. GEM led (off 0.4°C); AIFS ran 2°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 1 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 · 2026-07-17 23° 30° 23–30°
14d · 2026-07-18 22° 27° 22° 28° 22–28°
13d · 2026-07-19 22° 24° 27° 24° 22–27°
12d · 2026-07-20 20° 27° 25° 28° 20–28°
11d · 2026-07-21 25° 23° 23° 24° 23–25°
10d · 2026-07-22 25° 20° 26° 25° 20–26°
9d · 2026-07-23 23° 23° 27° 22° 26° 22–27°
8d · 2026-07-24 21° 23° 25° 22° 29° 21–29°
7d · 2026-07-25 20° 23° 22° 21° 22° 20–23°
6d · 2026-07-26 20° 22° 22° 22° 23° 22° 24° 20–24°
5d · 2026-07-27 20° 22° 23° 21° 25° 23° 24° 20–25°
4d · 2026-07-28 20° 22° 22° 22° 24° 21° 21° 20–24°
3d · 2026-07-29 21° 22° 22° 21° 22° 22° 20° 20–22°
2d · 2026-07-30 21° 22° 22° 21° 25° 22° 21° 21–25°
1d · 2026-07-31 21° 22° 22° 22° 20° 22° 21° 20–22°
0d · 2026-08-01 21° 22° 22° 23° 22° 22° 23° 21–23°
actual 23°

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.