The Spread

Was the forecast right for Paris on Mon Sep 7?

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

8 days out, 5 models put Paris's Mon Sep 7 high anywhere from 22° to 32°; by the final call the field had settled to a median of 29°. The day verified at 29° against the LFPB observations — cloudy.

ECMWF landed closest, off by 0.3°. AIFS ran 2° cold.

8 days out the models said 22–32; it hit 29. ECMWF led (off 0.3°C); AIFS ran 2°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 Mon Sep 7 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
8d · 2026-08-30 22° 29° 25° 24° 32° 22–32°
7d · 2026-08-31 25° 31° 27° 29° 32° 25–32°
6d · 2026-09-01 25° 27° 24° 27° 31° 26° 25° 24–31°
5d · 2026-09-02 29° 30° 26° 30° 29° 27° 26° 26–30°
4d · 2026-09-03 26° 30° 28° 30° 30° 29° 25° 25–30°
3d · 2026-09-04 26° 27° 28° 30° 29° 26° 27° 26–30°
2d · 2026-09-05 25° 28° 26° 29° 31° 27° 27° 25–31°
1d · 2026-09-06 26° 28° 27° 29° 29° 27° 27° 26–29°
0d · 2026-09-07 27° 29° 29° 29° 30° 28° 28° 27–30°
actual 29°

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.