The Spread

Was the forecast right for Washington on Tue Aug 11?

Washington, District of Columbia · daily high temperature in °C · forecasts from each model's archived runs, verified against ERA5

13 days out, 4 models put Washington's Tue Aug 11 high anywhere from 30° to 32°; by the final call the field had settled to a median of 32°. ERA5 says the day verified at 31° with 1.3 mm of precipitation — drizzle.

AIGFS landed closest, off by 0.3°. GEM ran 2° hot.

13 days out the models said 30–32; it hit 31. AIGFS led (off 0.3°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 Tue Aug 11 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 · 2026-07-27 32° 39° 32–39°
14d · 2026-07-28 32° 29° 31° 29–32°
13d · 2026-07-29 30° 31° 32° 32° 30–32°
12d · 2026-07-30 32° 30° 30° 28° 28–32°
11d · 2026-07-31 35° 33° 31° 35° 31–35°
10d · 2026-08-01 35° 29° 34° 35° 29–35°
9d · 2026-08-02 32° 24° 32° 32° 24–32°
8d · 2026-08-03 31° 33° 35° 33° 34° 31–35°
7d · 2026-08-04 32° 32° 35° 34° 37° 32–37°
6d · 2026-08-05 32° 32° 37° 31° 31° 37° 31–37°
5d · 2026-08-06 33° 31° 36° 35° 37° 34° 37° 31–37°
4d · 2026-08-07 31° 32° 35° 29° 35° 36° 36° 29–36°
3d · 2026-08-08 33° 33° 34° 33° 35° 28° 36° 28–36°
2d · 2026-08-09 32° 32° 34° 33° 33° 31° 36° 31–36°
1d · 2026-08-10 33° 32° 34° 32° 35° 30° 32° 30–35°
0d · 2026-08-11 31° 31° 32° 33° 31° 32° 32° 31–33°
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 ERA5 reanalysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.