The Spread

Was the forecast right for Paris on Tue Sep 8?

Paris, Île-de-France Region · daily high temperature in °C · forecasts from each model's archived runs, verified against the LFPB observations

9 days out, 5 models put Paris's Tue Sep 8 high anywhere from 20° to 29°; by the final call the field had settled to a median of 25°. The day verified at 27° against the LFPB observations, with 1.3 mm of precipitation — drizzle.

ICON landed closest, off by 0.6°. AIFS ran 3° cold.

9 days out the models said 20–29; it hit 27. ICON led (off 0.6°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 Tue Sep 8 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 Paris scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
9d · 2026-08-30 20° 23° 21° 29° 26° — — 20–29°
8d · 2026-08-31 24° 26° 28° 25° 29° — — 24–29°
7d · 2026-09-01 21° 22° 24° 22° 30° — — 21–30°
6d · 2026-09-02 21° 22° 26° 20° 24° 21° 25° 20–26°
5d · 2026-09-03 20° 21° 24° 21° 23° 23° 21° 20–24°
4d · 2026-09-04 22° 19° 20° 21° 23° 20° 20° 19–23°
3d · 2026-09-05 22° 20° 19° 21° 24° 20° 21° 19–24°
2d · 2026-09-06 23° 21° 22° 23° 24° 20° 24° 20–24°
1d · 2026-09-07 24° 26° 24° 26° 28° 26° 24° 24–28°
0d · 2026-09-08 24° 25° 25° 26° 28° 26° 25° 24–28°
actual 27°

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 Paris — 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 LFPB observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.