The Spread

Was the forecast right for Paris on Tue Sep 15?

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

14 days out, 4 models put Paris's Tue Sep 15 high anywhere from 63° to 89°; by the final call the field had settled to a median of 88°. The day verified at 91° against the LFPB observations — cloudy.

GFS landed closest, off by 1.0°. AIGFS ran 5° cold.

14 days out the models said 63–89; it hit 91. GFS led (off 1.0°F); AIGFS ran 5°F 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 15 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
15d · 2026-08-31 64° 92° 64–92°
14d · 2026-09-01 66° 63° 65° 89° 63–89°
13d · 2026-09-02 66° 68° 68° 77° 66–77°
12d · 2026-09-03 74° 63° 69° 84° 63–84°
11d · 2026-09-04 70° 69° 69° 81° 69–81°
10d · 2026-09-05 64° 76° 68° 76° 64–76°
9d · 2026-09-06 69° 72° 72° 77° 79° 69–79°
8d · 2026-09-07 73° 69° 73° 68° 81° 68–81°
7d · 2026-09-08 77° 78° 80° 76° 84° 76–84°
6d · 2026-09-09 78° 76° 79° 78° 83° 82° 76–83°
5d · 2026-09-10 75° 78° 83° 84° 88° 75° 85° 75–88°
4d · 2026-09-11 80° 79° 84° 87° 87° 82° 77° 77–87°
3d · 2026-09-12 85° 84° 87° 88° 88° 85° 87° 84–88°
2d · 2026-09-13 87° 84° 88° 87° 90° 86° 88° 84–90°
1d · 2026-09-14 86° 85° 89° 88° 90° 90° 88° 85–90°
0d · 2026-09-15 88° 86° 89° 88° 90° 90° 88° 86–90°
actual 91°

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.