Was the forecast right for Paris on Wed Sep 23?
Paris, Île-de-France Region · daily high temperature in °F · forecasts from each model's archived runs, verified against the LFPB observations
13 days out, 4 models put Paris's Wed Sep 23 high anywhere from 69° to 79°;by the final call, the day before, the field had settled to a median of 76°. The day verified at 81° against the LFPB observations — cloudy.
GFS landed closest, off by 3.5°. AIGFS ran 6° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 23 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-09-08 | — | 72° | — | — | 68° | — | — | 68–72° |
| 14d · 2026-09-09 | 77° | 77° | — | — | 76° | — | — | 76–77° |
| 13d · 2026-09-10 | 72° | 69° | 79° | — | 69° | — | — | 69–79° |
| 12d · 2026-09-11 | 78° | 64° | 64° | — | 78° | — | — | 64–78° |
| 11d · 2026-09-12 | 65° | 66° | 71° | — | 77° | — | — | 65–77° |
| 10d · 2026-09-13 | 72° | 64° | 66° | — | 69° | — | — | 64–72° |
| 9d · 2026-09-14 | 75° | 71° | 81° | 80° | 88° | — | — | 71–88° |
| 8d · 2026-09-15 | 75° | 72° | 79° | 78° | 75° | — | — | 72–79° |
| 7d · 2026-09-16 | 77° | 70° | 68° | 79° | 77° | — | — | 68–79° |
| 6d · 2026-09-17 | 75° | 70° | 70° | 76° | 76° | 78° | 71° | 70–78° |
| 5d · 2026-09-18 | 75° | 70° | 78° | 80° | 79° | 74° | 76° | 70–80° |
| 4d · 2026-09-19 | 78° | 71° | 79° | 80° | 77° | 69° | 75° | 69–80° |
| 3d · 2026-09-20 | 75° | 74° | 76° | 77° | 78° | 77° | 74° | 74–78° |
| 2d · 2026-09-21 | 75° | 73° | 74° | 77° | 77° | 78° | 75° | 73–78° |
| 1d · 2026-09-22 | 76° | 74° | 75° | 76° | 77° | 76° | 76° | 74–77° |
| actual | 81° |
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.