Was the forecast right for Denver on Sun Sep 6?
Denver, Colorado · daily high temperature in °F · forecasts from each model's archived runs, verified against the DEN observations
12 days out, 4 models put Denver's Sun Sep 6 high anywhere from 61° to 89°; by the final call the field had settled to a median of 90°. The day verified at 92° against the DEN observations — drizzle.
ECMWF landed closest, off by 1.1°. AIFS ran 4° cold.
What every model said, at every lead
Daily-high calls for Sun Sep 6 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 |
|---|---|---|---|---|---|---|---|---|
| 12d · 2026-08-25 | 69° | 72° | 89° | — | 61° | — | — | 61–89° |
| 11d · 2026-08-26 | 72° | 56° | 84° | — | 84° | — | — | 56–84° |
| 10d · 2026-08-27 | 69° | 86° | 90° | — | 85° | — | — | 69–90° |
| 9d · 2026-08-28 | 88° | 71° | 87° | — | 82° | — | — | 71–88° |
| 8d · 2026-08-29 | 86° | 94° | 87° | 82° | 88° | — | — | 82–94° |
| 7d · 2026-08-30 | 89° | 85° | 95° | 94° | 90° | — | — | 85–95° |
| 6d · 2026-08-31 | 86° | 90° | 95° | 89° | 89° | 84° | — | 84–95° |
| 5d · 2026-09-01 | 87° | 87° | 94° | 91° | 86° | 86° | 88° | 86–94° |
| 4d · 2026-09-02 | 88° | 89° | 92° | 90° | 92° | 87° | 93° | 87–93° |
| 3d · 2026-09-03 | 87° | 87° | 94° | 92° | 91° | 88° | 88° | 87–94° |
| 2d · 2026-09-04 | 89° | 87° | 94° | 91° | 89° | 89° | 92° | 87–94° |
| 1d · 2026-09-05 | 88° | 89° | 93° | 90° | 91° | 90° | 91° | 88–93° |
| 0d · 2026-09-06 | 88° | 88° | 91° | 90° | 90° | 90° | 90° | 88–91° |
| actual | 92° |
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.