Was the forecast right for Philadelphia on Wed Sep 2?
Philadelphia, Pennsylvania · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHL observations
8 days out, 5 models put Philadelphia's Wed Sep 2 high anywhere from 81° to 96°; by the final call the field had settled to a median of 80°. The day verified at 77° against the PHL observations, with 0.07 in of precipitation — drizzle.
GEM landed closest, off by 1.0°. UKMO ran 5° hot.
What every model said, at every lead
Daily-high calls for Wed Sep 2 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 Philadelphia scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 8d · 2026-08-25 | 90° | 81° | 96° | 94° | 87° | — | — | 81–96° |
| 7d · 2026-08-26 | 97° | 95° | 101° | 94° | 98° | — | — | 94–101° |
| 6d · 2026-08-27 | 95° | 94° | 95° | 96° | 94° | 92° | — | 92–96° |
| 5d · 2026-08-28 | 91° | 93° | 96° | 89° | 89° | 89° | 89° | 89–96° |
| 4d · 2026-08-29 | 88° | 92° | 94° | 88° | 81° | 88° | 93° | 81–94° |
| 3d · 2026-08-30 | 84° | 89° | 92° | 86° | 94° | 90° | 89° | 84–94° |
| 2d · 2026-08-31 | 80° | 81° | 85° | 79° | 81° | 82° | 85° | 79–85° |
| 1d · 2026-09-01 | 77° | 83° | 81° | 76° | 82° | 81° | 81° | 76–83° |
| 0d · 2026-09-02 | 79° | 81° | 82° | 78° | 80° | 79° | 82° | 78–82° |
| actual | 77° |
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 Philadelphia — 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 PHL observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.