Was the forecast right for Washington on Tue Sep 1?
Washington, District of Columbia · daily high temperature in °C · forecasts from each model's archived runs, verified against the DCA observations
13 days out, 4 models put Washington's Tue Sep 1 high anywhere from 29° to 36°;by the final call, the day before, the field had settled to a median of 35°. The day verified at 37° against the DCA observations — drizzle.
GFS landed closest, off by 0.3°. ICON ran 3° cool.
What every model said, at every lead
Daily-high calls for Tue Sep 1 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 · 2026-08-19 | 34° | 32° | 29° | — | 36° | — | — | 29–36° |
| 12d · 2026-08-20 | 23° | 35° | 31° | — | 30° | — | — | 23–35° |
| 11d · 2026-08-21 | 33° | 35° | 24° | — | 35° | — | — | 24–35° |
| 10d · 2026-08-22 | 35° | 29° | 30° | — | 27° | — | — | 27–35° |
| 9d · 2026-08-23 | 31° | 30° | 38° | 34° | 30° | — | — | 30–38° |
| 8d · 2026-08-24 | 36° | 34° | 37° | 36° | 27° | — | — | 27–37° |
| 7d · 2026-08-25 | 36° | 35° | 36° | 36° | 36° | — | — | 35–36° |
| 6d · 2026-08-26 | 35° | 35° | 37° | 36° | 34° | 36° | 34° | 34–37° |
| 5d · 2026-08-27 | 33° | 35° | 36° | 35° | 38° | 34° | 34° | 33–38° |
| 4d · 2026-08-28 | 34° | 34° | 36° | 37° | 32° | 34° | 33° | 32–37° |
| 3d · 2026-08-29 | 35° | 35° | 39° | 37° | 37° | 36° | 35° | 35–39° |
| 2d · 2026-08-30 | 35° | 34° | 39° | 36° | 38° | 36° | 35° | 34–39° |
| 1d · 2026-08-31 | 34° | 35° | 36° | 35° | 37° | 33° | 35° | 33–37° |
| actual | 37° |
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 DCA observations. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.