Was the forecast right for Philadelphia on Wed Sep 23?
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 Wed Sep 23 high anywhere from 63° to 83°;by the final call, the day before, the field had settled to a median of 67°. The day verified at 70° against the PHL observations, with 0.01 in of precipitation — drizzle.
GEM landed closest, off by 0.6°. GFS ran 4° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 23 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 · 2026-09-08 | — | 63° | — | — | 71° | — | — | 63–71° |
| 14d · 2026-09-09 | 83° | 65° | 63° | — | 80° | — | — | 63–83° |
| 13d · 2026-09-10 | 67° | 68° | 64° | — | 68° | — | — | 64–68° |
| 12d · 2026-09-11 | 69° | 72° | 74° | — | 59° | — | — | 59–74° |
| 11d · 2026-09-12 | 72° | 77° | 70° | — | 67° | — | — | 67–77° |
| 10d · 2026-09-13 | 74° | 73° | 73° | — | 70° | — | — | 70–74° |
| 9d · 2026-09-14 | 63° | 64° | 69° | 71° | 64° | — | — | 63–71° |
| 8d · 2026-09-15 | 69° | 75° | 75° | 69° | 69° | — | — | 69–75° |
| 7d · 2026-09-16 | 66° | 66° | 63° | 72° | 71° | — | — | 63–72° |
| 6d · 2026-09-17 | 64° | 57° | 69° | 59° | 64° | 66° | 65° | 57–69° |
| 5d · 2026-09-18 | 66° | 62° | 66° | 58° | 63° | 70° | 67° | 58–70° |
| 4d · 2026-09-19 | 68° | 65° | 62° | 58° | 60° | 64° | 68° | 58–68° |
| 3d · 2026-09-20 | 67° | 66° | 67° | 66° | 66° | 66° | 66° | 66–67° |
| 2d · 2026-09-21 | 67° | 64° | 67° | 68° | 66° | 66° | 68° | 64–68° |
| 1d · 2026-09-22 | 67° | 67° | 66° | 71° | 66° | 68° | 68° | 66–71° |
| actual | 70° |
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.