Was the forecast right for Philadelphia on Thu Sep 24?
Philadelphia, Pennsylvania · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHL observations
14 days out, 4 models put Philadelphia's Thu Sep 24 high anywhere from 62° to 77°;by the final call, the day before, the field had settled to a median of 66°. The day verified at 68° against the PHL observations — cloudy.
GFS landed closest, off by 0.0°. ECMWF ran 5° cool.
What every model said, at every lead
Daily-high calls for Thu Sep 24 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 · 2026-09-09 | — | 69° | — | — | 67° | — | — | 67–69° |
| 14d · 2026-09-10 | 74° | 62° | 63° | — | 77° | — | — | 62–77° |
| 13d · 2026-09-11 | 75° | 73° | 78° | — | 62° | — | — | 62–78° |
| 12d · 2026-09-12 | 71° | 75° | 68° | — | 73° | — | — | 68–75° |
| 11d · 2026-09-13 | 80° | 79° | 66° | — | 74° | — | — | 66–80° |
| 10d · 2026-09-14 | 69° | 75° | 70° | — | 66° | — | — | 66–75° |
| 9d · 2026-09-15 | 74° | 78° | 74° | 76° | 79° | — | — | 74–79° |
| 8d · 2026-09-16 | 66° | 71° | 65° | 75° | 81° | — | — | 65–81° |
| 7d · 2026-09-17 | 64° | 60° | 70° | 58° | 64° | — | — | 58–70° |
| 6d · 2026-09-18 | 65° | 57° | 67° | 56° | 62° | 67° | 66° | 56–67° |
| 5d · 2026-09-19 | 68° | 64° | 65° | 61° | 60° | 64° | 67° | 60–68° |
| 4d · 2026-09-20 | 66° | 64° | 63° | 61° | 66° | 64° | 65° | 61–66° |
| 3d · 2026-09-21 | 66° | 64° | 63° | 68° | 67° | 65° | 66° | 63–68° |
| 2d · 2026-09-22 | 66° | 64° | 66° | 68° | 68° | 64° | 66° | 64–68° |
| 1d · 2026-09-23 | 66° | 67° | 63° | 68° | 68° | 64° | 66° | 63–68° |
| actual | 68° |
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. 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.