Was the forecast right for Philadelphia on Sun Sep 27?
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 Sun Sep 27 high anywhere from 69° to 78°;by the final call, the day before, the field had settled to a median of 64°. The day verified at 67° against the PHL observations, with 1.58 in of precipitation — thunderstorms.
ECMWF landed closest, off by 1.7°. AIGFS ran 7° cool.
What every model said, at every lead
Daily-high calls for Sun Sep 27 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 · 2026-09-12 | — | 68° | — | — | 76° | — | — | 68–76° |
| 14d · 2026-09-13 | 77° | 78° | 74° | — | 69° | — | — | 69–78° |
| 13d · 2026-09-14 | 72° | 79° | 80° | — | 67° | — | — | 67–80° |
| 12d · 2026-09-15 | 73° | 81° | 76° | — | 86° | — | — | 73–86° |
| 11d · 2026-09-16 | 72° | 75° | 67° | — | 70° | — | — | 67–75° |
| 10d · 2026-09-17 | 63° | 70° | 64° | — | 68° | — | — | 63–70° |
| 9d · 2026-09-18 | 63° | 72° | 71° | 61° | 76° | — | — | 61–76° |
| 8d · 2026-09-19 | 78° | 74° | 66° | 60° | 58° | — | — | 58–78° |
| 7d · 2026-09-20 | 67° | 74° | 67° | 70° | 70° | — | — | 67–74° |
| 6d · 2026-09-21 | 62° | 75° | 66° | 73° | 79° | 62° | 71° | 62–79° |
| 5d · 2026-09-22 | 63° | 71° | 71° | 73° | 75° | 65° | 73° | 63–75° |
| 4d · 2026-09-23 | 64° | 74° | 62° | 73° | 63° | 61° | 62° | 61–74° |
| 3d · 2026-09-24 | 62° | 63° | 65° | 63° | 60° | 62° | 67° | 60–67° |
| 2d · 2026-09-25 | 64° | 61° | 64° | 60° | 60° | 64° | 64° | 60–64° |
| 1d · 2026-09-26 | 64° | 60° | 65° | 63° | 63° | 64° | 65° | 60–65° |
| actual | 67° |
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.