Was the forecast right for Paris on Fri Sep 4?
Paris, Île-de-France Region · daily high temperature in °C · forecasts from each model's archived runs, verified against the LFPB observations
5 days out, 7 models put Paris's Fri Sep 4 high anywhere from 25° to 31°;by the final call, the day before, the field had settled to a median of 27°. The day verified at 28° against the LFPB observations — cloudy.
ECMWF landed closest, off by 1.1°. GFS ran 3° warm.
What every model said, at every lead
Daily-high calls for Fri Sep 4 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 | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 5d · 2026-08-30 | 29° | 29° | 25° | 30° | 31° | 28° | 26° | 25–31° |
| 4d · 2026-08-31 | 28° | 28° | 28° | 29° | 28° | 30° | 29° | 28–30° |
| 3d · 2026-09-01 | 27° | 28° | 29° | 31° | 31° | 26° | 28° | 26–31° |
| 2d · 2026-09-02 | 27° | 27° | 26° | 30° | 30° | 28° | 26° | 26–30° |
| 1d · 2026-09-03 | 27° | 27° | 27° | 30° | 31° | 27° | 27° | 27–31° |
| actual | 28° |
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. 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.