The Spread

Was the forecast right for London on Fri Sep 11?

London, England · daily high temperature in °F · forecasts from each model's archived runs, verified against the EGLL observations

14 days out, 4 models put London's Fri Sep 11 high anywhere from 61° to 74°; by the final call the field had settled to a median of 70°. The day verified at 70° against the EGLL observations, with 0.08 in of precipitation — drizzle.

ECMWF landed closest, off by 0.1°. GFS ran 4° hot.

14 days out the models said 61–74; it hit 70. ECMWF led (off 0.1°F); GFS ran 4°F 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 Fri Sep 11 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 London scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-27 76° 69° 69–76°
14d · 2026-08-28 74° 66° 61° 66° 61–74°
13d · 2026-08-29 70° 61° 69° 80° 61–80°
12d · 2026-08-30 69° 69° 68° 66° 66–69°
11d · 2026-08-31 66° 65° 70° 68° 65–70°
10d · 2026-09-01 65° 70° 62° 64° 62–70°
9d · 2026-09-02 68° 66° 70° 66° 67° 66–70°
8d · 2026-09-03 66° 65° 66° 68° 72° 65–72°
7d · 2026-09-04 67° 61° 63° 71° 67° 61–71°
6d · 2026-09-05 68° 69° 67° 63° 60° 72° 70° 60–72°
5d · 2026-09-06 69° 71° 70° 72° 74° 73° 70° 69–74°
4d · 2026-09-07 69° 65° 66° 72° 71° 70° 69° 65–72°
3d · 2026-09-08 69° 69° 70° 72° 71° 71° 69° 69–72°
2d · 2026-09-09 70° 71° 69° 73° 74° 69° 70° 69–74°
1d · 2026-09-10 70° 71° 70° 72° 74° 72° 72° 70–74°
0d · 2026-09-11 70° 71° 70° 72° 74° 70° 70° 70–74°
actual 70°

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 London — 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 EGLL observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.