The Spread

Was the forecast right for Washington on Wed Aug 5?

Washington, District of Columbia · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

9 days out, 4 models put Washington's Wed Aug 5 high anywhere from 29° to 35°; by the final call the field had settled to a median of 30°. The day verified at 30° against the ECMWF IFS analysis, with 14.2 mm of precipitation — rain.

ICON landed closest, off by 0.1°. GEM ran 2° hot.

9 days out the models said 29–35; it hit 30. ICON led (off 0.1°C); GEM ran 2°C hot.
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 5 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 Washington scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
9d · 2026-07-27 29° 31° 32° 35° 29–35°
8d · 2026-07-28 32° 31° 28° 32° 35° 28–35°
7d · 2026-07-29 31° 30° 30° 31° 32° 30–32°
6d · 2026-07-30 26° 30° 31° 33° 31° 31° 26–33°
5d · 2026-07-31 32° 33° 34° 31° 33° 31° 32° 31–34°
4d · 2026-08-01 30° 32° 30° 30° 33° 30° 33° 30–33°
3d · 2026-08-02 30° 29° 30° 31° 31° 31° 32° 29–32°
2d · 2026-08-03 29° 29° 28° 31° 30° 28° 30° 28–31°
1d · 2026-08-04 30° 28° 29° 32° 28° 31° 31° 28–32°
0d · 2026-08-05 30° 29° 31° 32° 30° 30° 31° 29–32°
actual 30°

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 Washington — 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.