Was the forecast right for Denver on Wed Aug 19?
Denver, Colorado · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Denver's Wed Aug 19 high anywhere from 27° to 32°;by the final call, the day before, the field had settled to a median of 31°. The day verified at 33° against the ECMWF IFS analysis, with 0.8 mm of precipitation — drizzle.
GFS landed closest, off by 0.2°. GEM ran 3° cool.
What every model said, at every lead
Daily-high calls for Wed Aug 19 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 · 2026-08-04 | — | 19° | — | — | 39° | — | — | 19–39° |
| 14d · 2026-08-05 | 28° | 30° | 27° | — | 32° | — | — | 27–32° |
| 13d · 2026-08-06 | 26° | 28° | 28° | — | 35° | — | — | 26–35° |
| 12d · 2026-08-07 | 27° | 30° | 23° | — | 28° | — | — | 23–30° |
| 11d · 2026-08-08 | 24° | 30° | 29° | — | 31° | — | — | 24–31° |
| 10d · 2026-08-09 | 29° | 33° | 27° | — | 32° | — | — | 27–33° |
| 9d · 2026-08-10 | 30° | 29° | 34° | 33° | 36° | — | — | 29–36° |
| 8d · 2026-08-11 | 27° | 31° | 26° | 35° | 33° | — | — | 26–35° |
| 7d · 2026-08-12 | 30° | 27° | 31° | 33° | 26° | — | — | 26–33° |
| 6d · 2026-08-13 | 27° | 19° | 32° | 32° | 28° | 28° | 30° | 19–32° |
| 5d · 2026-08-14 | 28° | 27° | 26° | 31° | 28° | 29° | 31° | 26–31° |
| 4d · 2026-08-15 | 30° | 26° | 29° | 29° | 32° | 33° | 31° | 26–33° |
| 3d · 2026-08-16 | 31° | 30° | 31° | 31° | 32° | 31° | 31° | 30–32° |
| 2d · 2026-08-17 | 31° | 30° | 31° | 31° | 34° | 32° | 32° | 30–34° |
| 1d · 2026-08-18 | 31° | 31° | 31° | 30° | 33° | 31° | 33° | 30–33° |
| actual | 33° |
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 ECMWF IFS analysis (temperature_2m_max). 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.