The Spread

Was the forecast right for Washington on Sat Aug 15?

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

13 days out, 4 models put Washington's Sat Aug 15 high anywhere from 28° to 39°; by the final call the field had settled to a median of 32°. The ECMWF IFS analysis says the day verified at 31° — cloudy.

AIFS landed closest, off by 0.2°. GEM ran 2° hot.

13 days out the models said 28–39; it hit 31. AIFS led (off 0.2°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 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 Washington scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-07-31 28° 32° 28–32°
14d · 2026-08-01 30° 28° 33° 28–33°
13d · 2026-08-02 31° 28° 32° 39° 28–39°
12d · 2026-08-03 31° 29° 30° 25° 25–31°
11d · 2026-08-04 28° 28° 29° 28° 28–29°
10d · 2026-08-05 27° 28° 30° 24° 24–30°
9d · 2026-08-06 31° 27° 27° 33° 27–33°
8d · 2026-08-07 31° 28° 33° 23° 32° 23–33°
7d · 2026-08-08 28° 27° 30° 29° 29° 27–30°
6d · 2026-08-09 29° 28° 30° 27° 28° 25° 25–30°
5d · 2026-08-10 28° 27° 28° 27° 31° 27° 31° 27–31°
4d · 2026-08-11 30° 29° 27° 27° 31° 33° 29° 27–33°
3d · 2026-08-12 32° 24° 31° 27° 33° 29° 31° 24–33°
2d · 2026-08-13 31° 29° 31° 28° 30° 26° 30° 26–31°
1d · 2026-08-14 31° 30° 33° 33° 31° 32° 32° 30–33°
0d · 2026-08-15 32° 31° 32° 33° 32° 32° 30° 30–33°
actual 31°

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.