Was the forecast right for Denver on Fri Sep 11?
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 Fri Sep 11 high anywhere from 25° to 33°; by the final call the field had settled to a median of 32°. The day verified at 32° against the DEN observations — cloudy.
GFS landed closest, off by 0.1°. AIGFS ran 2° cold.
What every model said, at every lead
Daily-high calls for Fri Sep 11 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 | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-27 | — | 24° | — | — | 29° | — | — | 24–29° |
| 14d · 2026-08-28 | 28° | 30° | — | — | 35° | — | — | 28–35° |
| 13d · 2026-08-29 | 25° | 33° | 25° | — | 32° | — | — | 25–33° |
| 12d · 2026-08-30 | 28° | 24° | 28° | — | 34° | — | — | 24–34° |
| 11d · 2026-08-31 | 15° | 12° | 23° | — | 21° | — | — | 12–23° |
| 10d · 2026-09-01 | 25° | 24° | 27° | — | 30° | — | — | 24–30° |
| 9d · 2026-09-02 | 29° | 26° | 32° | — | 27° | — | — | 26–32° |
| 8d · 2026-09-03 | 31° | 26° | 27° | 26° | 32° | — | — | 26–32° |
| 7d · 2026-09-04 | 33° | 29° | 34° | 30° | 27° | — | — | 27–34° |
| 6d · 2026-09-05 | 32° | 29° | 33° | 30° | 31° | 31° | — | 29–33° |
| 5d · 2026-09-06 | 31° | 31° | 33° | 32° | 33° | 31° | 32° | 31–33° |
| 4d · 2026-09-07 | 31° | 31° | 33° | 30° | 31° | 31° | 30° | 30–33° |
| 3d · 2026-09-08 | 31° | 31° | 35° | 32° | 31° | 31° | 34° | 31–35° |
| 2d · 2026-09-09 | 32° | 31° | 35° | 31° | 30° | 31° | 31° | 30–35° |
| 1d · 2026-09-10 | 31° | 31° | 33° | 31° | 32° | 31° | 32° | 31–33° |
| 0d · 2026-09-11 | 32° | 30° | 33° | 31° | 32° | 31° | 32° | 30–33° |
| actual | 32° |
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.