The Spread

Was the forecast right for Denver on Sat Sep 12?

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 Sat Sep 12 high anywhere from 23° to 33°; by the final call the field had settled to a median of 28°. The day verified at 26° against the DEN observations — cloudy.

AIFS landed closest, off by 0.1°. UKMO ran 4° hot.

13 days out the models said 23–33; it hit 26. AIFS led (off 0.1°C); UKMO ran 4°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 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 Denver scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-28 31° 33° 31–33°
14d · 2026-08-29 30° 34° 34° 30–34°
13d · 2026-08-30 29° 23° 28° 33° 23–33°
12d · 2026-08-31 15° 15° 29° 29° 15–29°
11d · 2026-09-01 26° 24° 24° 26° 24–26°
10d · 2026-09-02 28° 24° 36° 24° 24–36°
9d · 2026-09-03 32° 28° 31° 26° 26–32°
8d · 2026-09-04 31° 19° 33° 26° 31° 19–33°
7d · 2026-09-05 29° 32° 26° 32° 31° 26–32°
6d · 2026-09-06 33° 33° 34° 31° 29° 32° 29–34°
5d · 2026-09-07 29° 32° 28° 34° 33° 34° 31° 28–34°
4d · 2026-09-08 27° 27° 26° 26° 26° 31° 30° 26–31°
3d · 2026-09-09 27° 27° 28° 28° 25° 28° 29° 25–29°
2d · 2026-09-10 28° 27° 30° 27° 26° 28° 31° 26–31°
1d · 2026-09-11 26° 26° 28° 28° 28° 30° 30° 26–30°
0d · 2026-09-12 26° 26° 30° 27° 28° 29° 31° 26–31°
actual 26°

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.