Was the forecast right for Philadelphia on Mon Sep 28?
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 Mon Sep 28 high anywhere from 73° to 82°;by the final call, the day before, the field had settled to a median of 66°. The day verified at 69° against the PHL observations, with 0.1 in of precipitation — drizzle.
UKMO landed closest, off by 2.1°. AIGFS ran 6° cool.
What every model said, at every lead
Daily-high calls for Mon Sep 28 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 · 2026-09-13 | — | 64° | — | — | 65° | — | — | 64–65° |
| 14d · 2026-09-14 | 73° | 75° | 82° | — | 76° | — | — | 73–82° |
| 13d · 2026-09-15 | 75° | 73° | 77° | — | 80° | — | — | 73–80° |
| 12d · 2026-09-16 | 74° | 67° | 68° | — | 75° | — | — | 67–75° |
| 11d · 2026-09-17 | 63° | 75° | 69° | — | 68° | — | — | 63–75° |
| 10d · 2026-09-18 | 64° | 69° | 75° | — | 77° | — | — | 64–77° |
| 9d · 2026-09-19 | 78° | 76° | 74° | 70° | 56° | — | — | 56–78° |
| 8d · 2026-09-20 | 68° | 75° | 64° | 73° | 75° | — | — | 64–75° |
| 7d · 2026-09-21 | 70° | 76° | 66° | 77° | 79° | — | — | 66–79° |
| 6d · 2026-09-22 | 71° | 74° | 66° | 77° | 76° | 69° | — | 66–77° |
| 5d · 2026-09-23 | 68° | 75° | 68° | 77° | 68° | 66° | 64° | 64–77° |
| 4d · 2026-09-24 | 67° | 72° | 70° | 70° | 61° | 64° | 68° | 61–72° |
| 3d · 2026-09-25 | 68° | 62° | 69° | 69° | 61° | 64° | 70° | 61–70° |
| 2d · 2026-09-26 | 67° | 61° | 67° | 65° | 61° | 64° | 68° | 61–68° |
| 1d · 2026-09-27 | 66° | 63° | 66° | 66° | 63° | 64° | 71° | 63–71° |
| actual | 69° |
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.