Was the forecast right for Denver on Sun Aug 9?
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 Sun Aug 9 high anywhere from 28° to 37°;by the final call, the day before, the field had settled to a median of 35°. The day verified at 36° against the ECMWF IFS analysis, with 0.8 mm of precipitation — drizzle.
ICON landed closest, off by 0.1°. GEM ran 2° cool.
What every model said, at every lead
Daily-high calls for Sun Aug 9 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 · 2026-07-25 | — | 29° | — | — | 35° | — | — | 29–35° |
| 14d · 2026-07-26 | 28° | 34° | 31° | — | 37° | — | — | 28–37° |
| 13d · 2026-07-27 | 30° | 32° | 37° | — | 38° | — | — | 30–38° |
| 12d · 2026-07-28 | 36° | 34° | 33° | — | 38° | — | — | 33–38° |
| 11d · 2026-07-29 | 35° | 30° | 35° | — | 37° | — | — | 30–37° |
| 10d · 2026-07-30 | 32° | 26° | 37° | — | 27° | — | — | 26–37° |
| 9d · 2026-07-31 | 33° | 34° | 37° | 34° | 37° | — | — | 33–37° |
| 8d · 2026-08-01 | 36° | 29° | 40° | 36° | 37° | — | — | 29–40° |
| 7d · 2026-08-02 | 36° | 35° | 40° | 34° | 37° | — | — | 34–40° |
| 6d · 2026-08-03 | 35° | 36° | 39° | 36° | 38° | 36° | 37° | 35–39° |
| 5d · 2026-08-04 | 35° | 33° | 38° | 35° | 37° | 37° | 36° | 33–38° |
| 4d · 2026-08-05 | 35° | 36° | 37° | 35° | 39° | 36° | 37° | 35–39° |
| 3d · 2026-08-06 | 35° | 36° | 36° | 34° | 38° | 37° | 36° | 34–38° |
| 2d · 2026-08-07 | 35° | 35° | 37° | 34° | 37° | 36° | 36° | 34–37° |
| 1d · 2026-08-08 | 35° | 35° | 36° | 34° | 37° | 36° | 35° | 34–37° |
| actual | 36° |
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.