Was the forecast right for Philadelphia on Wed Sep 16?
Philadelphia, Pennsylvania · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHL observations
13 days out, 4 models put Philadelphia's Wed Sep 16 high anywhere from 76° to 84°; by the final call the field had settled to a median of 81°. The day verified at 83° against the PHL observations — cloudy.
GFS landed closest, off by 0.0°. AIFS ran 3° cold.
What every model said, at every lead
Daily-high calls for Wed Sep 16 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-09-01 | — | 70° | — | — | 73° | — | — | 70–73° |
| 14d · 2026-09-02 | 82° | 77° | — | — | 95° | — | — | 77–95° |
| 13d · 2026-09-03 | 84° | 80° | 77° | — | 76° | — | — | 76–84° |
| 12d · 2026-09-04 | 80° | 73° | 91° | — | 92° | — | — | 73–92° |
| 11d · 2026-09-05 | 85° | 86° | 78° | — | 79° | — | — | 78–86° |
| 10d · 2026-09-06 | 79° | 89° | 80° | — | 66° | — | — | 66–89° |
| 9d · 2026-09-07 | 86° | 84° | 80° | — | 67° | — | — | 67–86° |
| 8d · 2026-09-08 | 85° | 77° | 90° | 74° | 86° | — | — | 74–90° |
| 7d · 2026-09-09 | 82° | 81° | 85° | 88° | 88° | — | — | 81–88° |
| 6d · 2026-09-10 | 82° | 84° | 79° | 81° | 90° | 85° | — | 79–90° |
| 5d · 2026-09-11 | 82° | 81° | 79° | 87° | 83° | 83° | 83° | 79–87° |
| 4d · 2026-09-12 | 82° | 78° | 80° | 84° | 82° | 83° | 83° | 78–84° |
| 3d · 2026-09-13 | 81° | 79° | 80° | 82° | 82° | 82° | 82° | 79–82° |
| 2d · 2026-09-14 | 81° | 79° | 79° | 82° | 83° | 82° | 81° | 79–83° |
| 1d · 2026-09-15 | 81° | 81° | 82° | 82° | 82° | 82° | 82° | 81–82° |
| 0d · 2026-09-16 | 80° | 81° | 81° | 81° | 83° | 81° | 82° | 80–83° |
| actual | 83° |
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.