Was the forecast right for Denver on Thu Sep 17?
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 Thu Sep 17 high anywhere from 68° to 76°; by the final call the field had settled to a median of 82°. The day verified at 84° against the DEN observations — drizzle.
GEM landed closest, off by 0.3°. AIGFS ran 6° cold.
What every model said, at every lead
Daily-high calls for Thu Sep 17 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 · 2026-09-02 | — | 81° | — | — | 69° | — | — | 69–81° |
| 14d · 2026-09-03 | 72° | 80° | — | — | 86° | — | — | 72–86° |
| 13d · 2026-09-04 | 76° | 75° | 68° | — | 68° | — | — | 68–76° |
| 12d · 2026-09-05 | 77° | 81° | 73° | — | 88° | — | — | 73–88° |
| 11d · 2026-09-06 | 79° | 66° | 82° | — | 78° | — | — | 66–82° |
| 10d · 2026-09-07 | 72° | 84° | 67° | — | 87° | — | — | 67–87° |
| 9d · 2026-09-08 | 78° | 61° | 79° | — | 80° | — | — | 61–80° |
| 8d · 2026-09-09 | 67° | 77° | 91° | 86° | 84° | — | — | 67–91° |
| 7d · 2026-09-10 | 63° | 70° | 68° | 80° | 76° | — | — | 63–80° |
| 6d · 2026-09-11 | 77° | 76° | 74° | 79° | 70° | 82° | — | 70–82° |
| 5d · 2026-09-12 | 75° | 74° | 73° | 81° | 75° | 77° | 75° | 73–81° |
| 4d · 2026-09-13 | 74° | 72° | 78° | 77° | 85° | 74° | 85° | 72–85° |
| 3d · 2026-09-14 | 76° | 74° | 78° | 82° | 84° | 75° | 79° | 74–84° |
| 2d · 2026-09-15 | 75° | 73° | 77° | 81° | 80° | 76° | 77° | 73–81° |
| 1d · 2026-09-16 | 80° | 78° | 82° | 84° | 86° | 79° | 78° | 78–86° |
| 0d · 2026-09-17 | 78° | 78° | 83° | 84° | 82° | 78° | 83° | 78–84° |
| actual | 84° |
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.