The Spread

Was the forecast right for Paris on Thu Sep 3?

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

4 days out, 7 models put Paris's Thu Sep 3 high anywhere from 26° to 30°; by the final call the field had settled to a median of 26°. The day verified at 27° against the LFPB observations — cloudy.

GFS landed closest, off by 0.4°. GEM ran 2° hot.

4 days out the models said 26–30; it hit 27. GFS led (off 0.4°C); GEM ran 2°C hot.
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 Paris scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
4d · 2026-08-30 26° 26° 26° 28° 30° 28° 27° 26–30°
3d · 2026-08-31 25° 27° 26° 29° 29° 28° 24° 24–29°
2d · 2026-09-01 24° 26° 25° 29° 28° 26° 25° 24–29°
1d · 2026-09-02 25° 25° 24° 28° 26° 25° 26° 24–28°
0d · 2026-09-03 26° 26° 25° 29° 27° 26° 26° 25–29°
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.