Was the forecast right for Denver on Fri Sep 18?
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 18 high anywhere from 78° to 90°; by the final call the field had settled to a median of 82°. The day verified at 86° against the DEN observations, with 0.86 in of precipitation — showers.
UKMO landed closest, off by 1.4°. AIGFS ran 7° cold.
What every model said, at every lead
Daily-high calls for Fri Sep 18 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 · 2026-09-03 | — | 81° | — | — | 79° | — | — | 79–81° |
| 14d · 2026-09-04 | 70° | 61° | — | — | 80° | — | — | 61–80° |
| 13d · 2026-09-05 | 79° | 87° | 78° | — | 90° | — | — | 78–90° |
| 12d · 2026-09-06 | 85° | 78° | 72° | — | 87° | — | — | 72–87° |
| 11d · 2026-09-07 | 81° | 75° | 69° | — | 86° | — | — | 69–86° |
| 10d · 2026-09-08 | 62° | 65° | 73° | — | 80° | — | — | 62–80° |
| 9d · 2026-09-09 | 72° | 74° | 79° | — | 88° | — | — | 72–88° |
| 8d · 2026-09-10 | 72° | 79° | 79° | 82° | 82° | — | — | 72–82° |
| 7d · 2026-09-11 | 80° | 78° | 81° | 85° | 72° | — | — | 72–85° |
| 6d · 2026-09-12 | 81° | 79° | 71° | 84° | 76° | 75° | — | 71–84° |
| 5d · 2026-09-13 | 81° | 80° | 80° | 80° | 77° | 80° | 83° | 77–83° |
| 4d · 2026-09-14 | 80° | 80° | 84° | 80° | 82° | 79° | 82° | 79–84° |
| 3d · 2026-09-15 | 78° | 79° | 81° | 82° | 82° | 82° | 81° | 78–82° |
| 2d · 2026-09-16 | 80° | 79° | 84° | 84° | 81° | 84° | 81° | 79–84° |
| 1d · 2026-09-17 | 79° | 77° | 79° | 83° | 80° | 82° | 83° | 77–83° |
| 0d · 2026-09-18 | 80° | 79° | 82° | 82° | 82° | 82° | 85° | 79–85° |
| actual | 86° |
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.