Was the forecast right for Denver on Fri Sep 11?
Denver, Colorado · daily high temperature in °F · 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 76° to 91°; by the final call the field had settled to a median of 89°. The day verified at 89° against the DEN observations — cloudy.
GFS landed closest, off by 0.2°. AIGFS ran 3° 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 | — | 75° | — | — | 85° | — | — | 75–85° |
| 14d · 2026-08-28 | 83° | 87° | — | — | 95° | — | — | 83–95° |
| 13d · 2026-08-29 | 77° | 91° | 76° | — | 90° | — | — | 76–91° |
| 12d · 2026-08-30 | 83° | 75° | 82° | — | 94° | — | — | 75–94° |
| 11d · 2026-08-31 | 59° | 54° | 73° | — | 70° | — | — | 54–73° |
| 10d · 2026-09-01 | 77° | 74° | 80° | — | 87° | — | — | 74–87° |
| 9d · 2026-09-02 | 84° | 79° | 90° | — | 81° | — | — | 79–90° |
| 8d · 2026-09-03 | 88° | 78° | 81° | 78° | 89° | — | — | 78–89° |
| 7d · 2026-09-04 | 92° | 84° | 93° | 85° | 81° | — | — | 81–93° |
| 6d · 2026-09-05 | 90° | 85° | 92° | 86° | 88° | 87° | — | 85–92° |
| 5d · 2026-09-06 | 88° | 89° | 92° | 89° | 91° | 88° | 89° | 88–92° |
| 4d · 2026-09-07 | 88° | 87° | 91° | 87° | 88° | 88° | 86° | 86–91° |
| 3d · 2026-09-08 | 87° | 87° | 96° | 89° | 88° | 88° | 93° | 87–96° |
| 2d · 2026-09-09 | 89° | 87° | 94° | 88° | 87° | 87° | 88° | 87–94° |
| 1d · 2026-09-10 | 89° | 88° | 92° | 87° | 89° | 89° | 90° | 87–92° |
| 0d · 2026-09-11 | 90° | 86° | 91° | 88° | 89° | 88° | 90° | 86–91° |
| actual | 89° |
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.