Was the forecast right for Washington on Sun Sep 20?
Washington, District of Columbia · daily high temperature in °F · forecasts from each model's archived runs, verified against the DCA observations
13 days out, 4 models put Washington's Sun Sep 20 high anywhere from 70° to 79°; by the final call the field had settled to a median of 84°. The day verified at 84° against the DCA observations — thunderstorms.
GEM landed closest, off by 0.4°. ECMWF ran 3° warm.
What every model said, at every lead
Daily-high calls for Sun Sep 20 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-09-05 | — | 77° | — | — | 94° | — | — | 77–94° |
| 14d · 2026-09-06 | 75° | 67° | — | — | 73° | — | — | 67–75° |
| 13d · 2026-09-07 | 79° | 70° | 79° | — | 75° | — | — | 70–79° |
| 12d · 2026-09-08 | 71° | 72° | 73° | — | 73° | — | — | 71–73° |
| 11d · 2026-09-09 | 72° | 89° | 91° | — | 84° | — | — | 72–91° |
| 10d · 2026-09-10 | 86° | 76° | 74° | — | 80° | — | — | 74–86° |
| 9d · 2026-09-11 | 75° | 78° | 81° | — | 72° | — | — | 72–81° |
| 8d · 2026-09-12 | 78° | 74° | 90° | 84° | 78° | — | — | 74–90° |
| 7d · 2026-09-13 | 75° | 71° | 89° | 80° | 90° | — | — | 71–90° |
| 6d · 2026-09-14 | 82° | 86° | 92° | 88° | 98° | 76° | — | 76–98° |
| 5d · 2026-09-15 | 83° | 83° | 82° | 87° | 87° | 84° | 82° | 82–87° |
| 4d · 2026-09-16 | 80° | 88° | 83° | 84° | 89° | 84° | 84° | 80–89° |
| 3d · 2026-09-17 | 80° | 83° | 86° | 85° | 85° | 85° | 84° | 80–86° |
| 2d · 2026-09-18 | 82° | 82° | 86° | 86° | 82° | 83° | 85° | 82–86° |
| 1d · 2026-09-19 | 83° | 84° | 87° | 84° | 88° | 86° | 86° | 83–88° |
| 0d · 2026-09-20 | 84° | 85° | 87° | 84° | 86° | 84° | 84° | 84–87° |
| actual | 84° |
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. Archive depth varies by city; receipts exist only for dates the archive watched arrive.