The Spread

Was the forecast right for Denver on Thu Aug 13?

Denver, Colorado · daily high temperature in °C · forecasts from each model's archived runs, verified against ERA5

13 days out, 4 models put Denver's Thu Aug 13 high anywhere from 26° to 34°; by the final call the field had settled to a median of 26°. ERA5 says the day verified at 27° with 5.3 mm of precipitation — rain.

ECMWF landed closest, off by 0.4°. AIFS ran 4° cold.

13 days out the models said 26–34; it hit 27. ECMWF led (off 0.4°C); AIFS ran 4°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 Thu Aug 13 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 · 2026-07-29 30° 37° 30–37°
14d · 2026-07-30 32° 29° 36° 29–36°
13d · 2026-07-31 34° 26° 27° 31° 26–34°
12d · 2026-08-01 28° 23° 33° 32° 23–33°
11d · 2026-08-02 25° 26° 31° 33° 25–33°
10d · 2026-08-03 27° 24° 21° 38° 21–38°
9d · 2026-08-04 25° 29° 36° 31° 25–36°
8d · 2026-08-05 29° 26° 30° 28° 33° 26–33°
7d · 2026-08-06 19° 30° 29° 25° 31° 19–31°
6d · 2026-08-07 17° 27° 32° 24° 36° 33° 17–36°
5d · 2026-08-08 24° 22° 30° 29° 24° 32° 27° 22–32°
4d · 2026-08-09 25° 24° 28° 29° 33° 31° 32° 24–33°
3d · 2026-08-10 23° 26° 30° 29° 30° 28° 29° 23–30°
2d · 2026-08-11 25° 27° 28° 29° 33° 30° 27° 25–33°
1d · 2026-08-12 25° 26° 27° 28° 28° 26° 28° 25–28°
0d · 2026-08-13 23° 24° 26° 26° 28° 26° 24° 23–28°
actual 27°

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 ERA5 reanalysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.