The Spread

Was the forecast right for Denver on Wed Sep 16?

Denver, Colorado · daily high temperature in °C · forecasts from each model's archived runs, verified against the DEN observations

13 days out, 4 models put Denver's Wed Sep 16 high anywhere from 22° to 32°; by the final call the field had settled to a median of 27°. The day verified at 28° against the DEN observations — rain.

ECMWF landed closest, off by 1.1°. ICON ran 3° cold.

13 days out the models said 22–32; it hit 28. ECMWF led (off 1.1°C); ICON ran 3°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 Wed Sep 16 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 Denver scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-09-01 26° 29° 26–29°
14d · 2026-09-02 28° 22° 32° 22–32°
13d · 2026-09-03 22° 26° 32° 25° 22–32°
12d · 2026-09-04 23° 28° 29° 29° 23–29°
11d · 2026-09-05 24° 25° 32° 29° 24–32°
10d · 2026-09-06 26° 28° 30° 30° 26–30°
9d · 2026-09-07 28° 25° 23° 29° 23–29°
8d · 2026-09-08 31° 29° 30° 31° 34° 29–34°
7d · 2026-09-09 30° 29° 32° 30° 32° 29–32°
6d · 2026-09-10 26° 23° 23° 28° 25° 19° 19–28°
5d · 2026-09-11 28° 25° 27° 29° 30° 24° 21° 21–30°
4d · 2026-09-12 25° 25° 25° 29° 29° 25° 29° 25–29°
3d · 2026-09-13 25° 24° 29° 29° 28° 27° 30° 24–30°
2d · 2026-09-14 25° 24° 30° 29° 28° 28° 28° 24–30°
1d · 2026-09-15 25° 26° 29° 28° 29° 26° 31° 25–31°
0d · 2026-09-16 27° 27° 29° 27° 27° 25° 31° 25–31°
actual 28°

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