The Spread

Was the forecast right for Philadelphia on Thu Sep 3?

Philadelphia, Pennsylvania · daily high temperature in °C · forecasts from each model's archived runs, verified against the PHL observations

9 days out, 4 models put Philadelphia's Thu Sep 3 high anywhere from 28° to 34°; by the final call the field had settled to a median of 31°. The day verified at 32° against the PHL observations, with 34.0 mm of precipitation — thunderstorms.

AIGFS landed closest, off by 0.8°. AIFS ran 3° cold.

9 days out the models said 28–34; it hit 32. AIGFS led (off 0.8°C); AIFS ran 3°C cold.
The shareable card for this receipt — what this page looks like pasted into a thread.

What every model said, at every lead

Daily-high calls for Thu Sep 3 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 AIFSAIGFSECMWFGEMGFSICONUKMO Range
9d · 2026-08-25 31° 28° 34° — 29° — — 28–34°
8d · 2026-08-26 31° 31° 37° 27° 37° — — 27–37°
7d · 2026-08-27 29° 30° 27° 30° 32° — — 27–32°
6d · 2026-08-28 29° 31° 36° 30° 37° 31° — 29–37°
5d · 2026-08-29 34° 33° 39° 32° 31° 33° 35° 31–39°
4d · 2026-08-30 32° 33° 34° 33° 35° 34° 33° 32–35°
3d · 2026-08-31 31° 32° 33° 33° 33° 34° 34° 31–34°
2d · 2026-09-01 29° 32° 31° 30° 31° 30° 34° 29–34°
1d · 2026-09-02 30° 32° 31° 29° 34° 31° 33° 29–34°
0d · 2026-09-03 29° 31° 31° 29° 34° 31° 33° 29–34°
actual 32°

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.