The Spread

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

13 days out, 4 models put Denver's Wed Aug 19 high anywhere from 25° to 32°; by the final call the field had settled to a median of 32°. The day verified at 33° against the ECMWF IFS analysis, with 0.8 mm of precipitation — drizzle.

UKMO landed closest, off by 0.0°. GEM ran 2° cold.

13 days out the models said 25–32; it hit 33. UKMO led (off 0.0°C); GEM ran 2°C cold.
The shareable card for this receipt — what this page looks like pasted into a thread.

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 AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-04 20° 39° 20–39°
14d · 2026-08-05 26° 28° 32° 26–32°
13d · 2026-08-06 25° 29° 26° 32° 25–32°
12d · 2026-08-07 28° 33° 27° 36° 27–36°
11d · 2026-08-08 26° 34° 29° 25° 25–34°
10d · 2026-08-09 28° 26° 30° 36° 26–36°
9d · 2026-08-10 28° 32° 33° 34° 28–34°
8d · 2026-08-11 27° 31° 33° 33° 35° 27–35°
7d · 2026-08-12 30° 32° 31° 34° 37° 30–37°
6d · 2026-08-13 27° 27° 32° 32° 33° 31° 27–33°
5d · 2026-08-14 28° 24° 28° 27° 25° 24° 31° 24–31°
4d · 2026-08-15 27° 23° 27° 29° 29° 31° 32° 23–32°
3d · 2026-08-16 30° 27° 29° 31° 34° 31° 31° 27–34°
2d · 2026-08-17 31° 30° 31° 30° 34° 32° 32° 30–34°
1d · 2026-08-18 31° 31° 31° 31° 36° 32° 33° 31–36°
0d · 2026-08-19 31° 31° 32° 31° 33° 32° 33° 31–33°
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). Archive depth varies by city; receipts exist only for dates the archive watched arrive.