The Spread

Was the forecast right for Washington on Thu Aug 13?

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 Thu Aug 13 high anywhere from 29° to 38°; by the final call the field had settled to a median of 33°. ERA5 says the day verified at 32° with 1.8 mm of precipitation — drizzle.

UKMO landed closest, off by 0.1°. GEM ran 3° hot.

13 days out the models said 29–38; it hit 32. UKMO led (off 0.1°C); GEM ran 3°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 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 Washington scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-07-29 30° 33° 30–33°
14d · 2026-07-30 34° 32° 22° 22–34°
13d · 2026-07-31 35° 29° 31° 38° 29–38°
12d · 2026-08-01 29° 27° 35° 32° 27–35°
11d · 2026-08-02 25° 28° 36° 35° 25–36°
10d · 2026-08-03 30° 30° 36° 30° 30–36°
9d · 2026-08-04 32° 32° 26° 28° 26–32°
8d · 2026-08-05 33° 29° 32° 29° 26° 26–33°
7d · 2026-08-06 31° 32° 32° 34° 34° 31–34°
6d · 2026-08-07 31° 32° 29° 26° 31° 33° 26–33°
5d · 2026-08-08 32° 32° 33° 31° 34° 33° 36° 31–36°
4d · 2026-08-09 32° 33° 32° 30° 33° 33° 33° 30–33°
3d · 2026-08-10 32° 32° 32° 29° 34° 31° 33° 29–34°
2d · 2026-08-11 33° 32° 32° 31° 32° 33° 33° 31–33°
1d · 2026-08-12 33° 31° 32° 34° 33° 32° 33° 31–34°
0d · 2026-08-13 33° 33° 34° 35° 34° 32° 32° 32–35°
actual 32°

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.