Was the forecast right for Philadelphia on Wed Sep 30?
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 30 high anywhere from 62° to 83°;by the final call, the day before, the field had settled to a median of 77°. The day verified at 77° against the PHL observations — cloudy.
AIGFS landed closest, off by 0.3°. UKMO ran 3° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 30 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 · 2026-09-15 | — | 66° | — | — | 89° | — | — | 66–89° |
| 14d · 2026-09-16 | 76° | 62° | 66° | — | 83° | — | — | 62–83° |
| 13d · 2026-09-17 | 69° | 79° | 80° | — | 71° | — | — | 69–80° |
| 12d · 2026-09-18 | 77° | 74° | 74° | — | 72° | — | — | 72–77° |
| 11d · 2026-09-19 | 75° | 76° | 62° | — | 63° | — | — | 62–76° |
| 10d · 2026-09-20 | 77° | 78° | 73° | — | 82° | — | — | 73–82° |
| 9d · 2026-09-21 | 79° | 84° | 70° | 80° | 82° | — | — | 70–84° |
| 8d · 2026-09-22 | 80° | 80° | 74° | 83° | 83° | — | — | 74–83° |
| 7d · 2026-09-23 | 75° | 79° | 76° | 83° | 83° | — | — | 75–83° |
| 6d · 2026-09-24 | 79° | 79° | 80° | 80° | 78° | 78° | 76° | 76–80° |
| 5d · 2026-09-25 | 79° | 79° | 78° | 76° | 79° | 75° | 75° | 75–79° |
| 4d · 2026-09-26 | 79° | 78° | 77° | 76° | 78° | 77° | 76° | 76–79° |
| 3d · 2026-09-27 | 78° | 77° | 77° | 77° | 80° | 76° | 75° | 75–80° |
| 2d · 2026-09-28 | 78° | 78° | 77° | 78° | 79° | 77° | 76° | 76–79° |
| 1d · 2026-09-29 | 76° | 77° | 77° | 77° | 79° | 78° | 74° | 74–79° |
| 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. 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.