Was the forecast right for Washington on Mon Aug 17?
Washington, District of Columbia · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
13 days out, 4 models put Washington's Mon Aug 17 high anywhere from 80° to 87°; by the final call the field had settled to a median of 90°. The ECMWF IFS analysis says the day verified at 90° with 0.5 in of precipitation — thunderstorms.
ICON landed closest, off by 0.1°. GEM ran 4° hot.
What every model said, at every lead
Daily-high calls for Mon Aug 17 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 · 2026-08-02 | — | 87° | — | — | 97° | — | — | 87–97° |
| 14d · 2026-08-03 | 92° | 73° | — | — | 88° | — | — | 73–92° |
| 13d · 2026-08-04 | 80° | 80° | 87° | — | 86° | — | — | 80–87° |
| 12d · 2026-08-05 | 83° | 77° | 77° | — | 87° | — | — | 77–87° |
| 11d · 2026-08-06 | 83° | 83° | 81° | — | 83° | — | — | 81–83° |
| 10d · 2026-08-07 | 77° | 87° | 81° | — | 84° | — | — | 77–87° |
| 9d · 2026-08-08 | 88° | 93° | 85° | — | 75° | — | — | 75–93° |
| 8d · 2026-08-09 | 84° | 88° | 96° | 87° | 86° | — | — | 84–96° |
| 7d · 2026-08-10 | 87° | 89° | 85° | 91° | 85° | — | — | 85–91° |
| 6d · 2026-08-11 | 90° | 90° | 90° | 88° | 87° | 89° | — | 87–90° |
| 5d · 2026-08-12 | 88° | 86° | 88° | 84° | 90° | 83° | 92° | 83–92° |
| 4d · 2026-08-13 | 90° | 88° | 90° | 88° | 88° | 87° | 90° | 87–90° |
| 3d · 2026-08-14 | 90° | 88° | 93° | 85° | 92° | 90° | 92° | 85–93° |
| 2d · 2026-08-15 | 90° | 90° | 88° | 84° | 93° | 91° | 92° | 84–93° |
| 1d · 2026-08-16 | 90° | 90° | 87° | 94° | 87° | 90° | 91° | 87–94° |
| 0d · 2026-08-17 | 90° | 90° | 88° | 94° | 91° | 90° | 91° | 88–94° |
| actual | 90° |
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 ECMWF IFS analysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.