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
13 days out, 4 models put Denver's Sun Sep 6 high anywhere from 59° to 84°;by the final call, the day before, the field had settled to a median of 90°. The day verified at 92° against the DEN observations — drizzle.
ECMWF landed closest, off by 0.6°. AIFS ran 5° cool.
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 |
|---|---|---|---|---|---|---|---|---|
| 13d · 2026-08-24 | 82° | 59° | 80° | — | 84° | — | — | 59–84° |
| 12d · 2026-08-25 | 54° | 74° | 84° | — | 87° | — | — | 54–87° |
| 11d · 2026-08-26 | 72° | 76° | 95° | — | 80° | — | — | 72–95° |
| 10d · 2026-08-27 | 81° | 74° | 100° | — | 90° | — | — | 74–100° |
| 9d · 2026-08-28 | 84° | 92° | 91° | 88° | 90° | — | — | 84–92° |
| 8d · 2026-08-29 | 88° | 89° | 93° | 94° | 85° | — | — | 85–94° |
| 7d · 2026-08-30 | 89° | 83° | 92° | 88° | 92° | — | — | 83–92° |
| 6d · 2026-08-31 | 90° | 84° | 85° | 90° | 85° | 90° | 78° | 78–90° |
| 5d · 2026-09-01 | 88° | 87° | 90° | 90° | 89° | 82° | 91° | 82–91° |
| 4d · 2026-09-02 | 88° | 87° | 93° | 91° | 87° | 88° | 90° | 87–93° |
| 3d · 2026-09-03 | 87° | 87° | 91° | 92° | 91° | 88° | 91° | 87–92° |
| 2d · 2026-09-04 | 89° | 90° | 92° | 91° | 90° | 89° | 91° | 89–92° |
| 1d · 2026-09-05 | 87° | 88° | 93° | 90° | 90° | 89° | 91° | 87–93° |
| 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. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.