Was the forecast right for Washington on Sun Aug 9?
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 Sun Aug 9 high anywhere from 26° to 33°; by the final call the field had settled to a median of 35°. ERA5 says the day verified at 33° — partly cloudy.
ICON landed closest, off by 0.7°. GEM ran 3° hot.
What every model said, at every lead
Daily-high calls for Sun Aug 9 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 | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 13d · 2026-07-27 | 33° | 26° | 32° | — | 33° | — | — | 26–33° |
| 12d · 2026-07-28 | 32° | 33° | 31° | — | 38° | — | — | 31–38° |
| 11d · 2026-07-29 | 31° | 32° | 33° | — | 34° | — | — | 31–34° |
| 10d · 2026-07-30 | 31° | 35° | 34° | — | 34° | — | — | 31–35° |
| 9d · 2026-07-31 | 33° | 34° | 32° | — | 36° | — | — | 32–36° |
| 8d · 2026-08-01 | 33° | 35° | 33° | 34° | 36° | — | — | 33–36° |
| 7d · 2026-08-02 | 33° | 31° | 32° | 33° | 37° | — | — | 31–37° |
| 6d · 2026-08-03 | 33° | 33° | 31° | 34° | 37° | 33° | — | 31–37° |
| 5d · 2026-08-04 | 33° | 33° | 31° | 29° | 36° | 36° | 33° | 29–36° |
| 4d · 2026-08-05 | 34° | 33° | 32° | 29° | 35° | 34° | 33° | 29–35° |
| 3d · 2026-08-06 | 34° | 33° | 32° | 31° | 35° | 34° | 33° | 31–35° |
| 2d · 2026-08-07 | 34° | 32° | 34° | 33° | 36° | 34° | 34° | 32–36° |
| 1d · 2026-08-08 | 35° | 34° | 34° | 35° | 36° | 35° | 34° | 34–36° |
| 0d · 2026-08-09 | 35° | 35° | 34° | 36° | 36° | 34° | 34° | 34–36° |
| actual | 33° |
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.