The Spread

Was the forecast right for Seattle on Sat Sep 12?

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

14 days out, 4 models put Seattle's Sat Sep 12 high anywhere from 16° to 23°; by the final call the field had settled to a median of 19°. The day verified at 19° against the SEA observations, with 3.0 mm of precipitation — drizzle.

UKMO landed closest, off by 0.1°. AIFS ran 2° cold.

14 days out the models said 16–23; it hit 19. UKMO led (off 0.1°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 Sep 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 · 2026-08-28 18° 20° 18–20°
14d · 2026-08-29 16° 21° 21° 23° 16–23°
13d · 2026-08-30 20° 24° 21° 31° 20–31°
12d · 2026-08-31 19° 20° 17° 17° 17–20°
11d · 2026-09-01 19° 21° 17° 25° 17–25°
10d · 2026-09-02 18° 18° 24° 22° 18–24°
9d · 2026-09-03 21° 21° 17° 18° 22° 17–22°
8d · 2026-09-04 20° 17° 21° 20° 17° 17–21°
7d · 2026-09-05 17° 19° 20° 20° 25° 17–25°
6d · 2026-09-06 16° 24° 18° 19° 19° 24° 18° 16–24°
5d · 2026-09-07 15° 20° 17° 19° 18° 19° 19° 15–20°
4d · 2026-09-08 15° 20° 17° 15° 22° 17° 16° 15–22°
3d · 2026-09-09 17° 18° 17° 20° 20° 15° 17° 15–20°
2d · 2026-09-10 17° 19° 19° 19° 21° 15° 19° 15–21°
1d · 2026-09-11 17° 19° 20° 22° 22° 19° 18° 17–22°
0d · 2026-09-12 17° 19° 20° 20° 20° 18° 19° 17–20°
actual 19°

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