The Spread

Was the forecast right for Denver on Fri Sep 4?

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

10 days out, 4 models put Denver's Fri Sep 4 high anywhere from 19° to 33°; by the final call the field had settled to a median of 33°. The day verified at 34° against the DEN observations — partly cloudy.

ECMWF landed closest, off by 0.1°. GFS ran 3° cold.

10 days out the models said 19–33; it hit 34. ECMWF led (off 0.1°C); GFS 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 Fri Sep 4 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
10d · 2026-08-25 27° 19° 33° — 31° — — 19–33°
9d · 2026-08-26 21° 29° 29° — 27° — — 21–29°
8d · 2026-08-27 29° 31° 35° 24° 29° — — 24–35°
7d · 2026-08-28 32° 30° 34° 33° 31° — — 30–34°
6d · 2026-08-29 32° 31° 33° 33° 28° 30° — 28–33°
5d · 2026-08-30 33° 30° 33° 32° 33° 31° 34° 30–34°
4d · 2026-08-31 33° 31° 31° 31° 30° 29° 33° 29–33°
3d · 2026-09-01 33° 32° 33° 32° 32° 31° 31° 31–33°
2d · 2026-09-02 33° 32° 33° 32° 33° 31° 33° 31–33°
1d · 2026-09-03 33° 32° 33° 32° 32° 32° 33° 32–33°
0d · 2026-09-04 34° 32° 34° 33° 31° 32° 33° 31–34°
actual 34°

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.