Was the forecast right for Philadelphia on Fri Aug 28?
Philadelphia, Pennsylvania · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHL observations
3 days out, 7 models put Philadelphia's Fri Aug 28 high anywhere from 80° to 87°;by the final call, the day before, the field had settled to a median of 84°. The day verified at 87° against the PHL observations — thunderstorms.
GFS landed closest, off by 0.8°. ICON ran 6° cool.
What every model said, at every lead
Daily-high calls for Fri Aug 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 |
|---|---|---|---|---|---|---|---|---|
| 3d · 2026-08-25 | 85° | 85° | 86° | 85° | 87° | 80° | 87° | 80–87° |
| 2d · 2026-08-26 | 85° | 86° | 81° | 85° | 89° | 79° | 85° | 79–89° |
| 1d · 2026-08-27 | 84° | 86° | 81° | 83° | 88° | 80° | 86° | 80–88° |
| actual | 87° |
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.