The Spread

Was the forecast right for Denver on Sat Aug 15?

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 Sat Aug 15 high anywhere from 28° to 35°; by the final call the field had settled to a median of 27°. The ECMWF IFS analysis says the day verified at 27° with 3.0 mm of precipitation — drizzle.

AIGFS landed closest, off by 0.4°. GEM ran 4° cold.

13 days out the models said 28–35; it hit 27. AIGFS led (off 0.4°C); GEM 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 Sat Aug 15 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 · 2026-07-31 31° 22° 22–31°
14d · 2026-08-01 23° 25° 35° 23–35°
13d · 2026-08-02 29° 28° 32° 35° 28–35°
12d · 2026-08-03 23° 33° 25° 33° 23–33°
11d · 2026-08-04 28° 29° 33° 34° 28–34°
10d · 2026-08-05 26° 27° 25° 31° 25–31°
9d · 2026-08-06 20° 26° 27° 30° 20–30°
8d · 2026-08-07 18° 29° 24° 26° 30° 18–30°
7d · 2026-08-08 25° 29° 23° 28° 33° 23–33°
6d · 2026-08-09 25° 29° 24° 26° 31° 29° 24–31°
5d · 2026-08-10 26° 29° 26° 28° 30° 29° 30° 26–30°
4d · 2026-08-11 26° 28° 27° 26° 30° 29° 30° 26–30°
3d · 2026-08-12 25° 28° 27° 26° 26° 29° 28° 25–29°
2d · 2026-08-13 26° 27° 26° 24° 31° 30° 29° 24–31°
1d · 2026-08-14 26° 27° 27° 25° 30° 30° 30° 25–30°
0d · 2026-08-15 26° 27° 24° 23° 30° 28° 28° 23–30°
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 the ECMWF IFS analysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.