Was the forecast right for Denver on Tue Aug 4?
Denver, Colorado · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
10 days out, 4 models put Denver's Tue Aug 4 high anywhere from 24° to 39°;by the final call, the day before, the field had settled to a median of 26°. The day verified at 24° against the ECMWF IFS analysis, with 0.3 mm of precipitation — drizzle.
AIFS landed closest, off by 0.3°. ECMWF ran 2° warm.
What every model said, at every lead
Daily-high calls for Tue Aug 4 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 |
|---|---|---|---|---|---|---|---|---|
| 10d · 2026-07-25 | 24° | 28° | 29° | — | 39° | — | — | 24–39° |
| 9d · 2026-07-26 | 28° | 33° | 30° | 32° | 39° | — | — | 28–39° |
| 8d · 2026-07-27 | 29° | 26° | 33° | 32° | 30° | — | — | 26–33° |
| 7d · 2026-07-28 | 29° | 29° | 32° | 32° | 29° | — | — | 29–32° |
| 6d · 2026-07-29 | 23° | 22° | 29° | 29° | 29° | 33° | 33° | 22–33° |
| 5d · 2026-07-30 | 23° | 23° | 30° | 26° | 28° | 25° | 29° | 23–30° |
| 4d · 2026-07-31 | 22° | 23° | 27° | 22° | 31° | 28° | 29° | 22–31° |
| 3d · 2026-08-01 | 26° | 25° | 28° | 22° | 31° | 26° | 27° | 22–31° |
| 2d · 2026-08-02 | 24° | 25° | 26° | 21° | 31° | 27° | 26° | 21–31° |
| 1d · 2026-08-03 | 24° | 25° | 27° | 26° | 26° | 25° | 26° | 24–27° |
| actual | 24° |
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.