The Spread

Was the forecast right for London on Mon Sep 14?

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 Mon Sep 14 high anywhere from 62° to 79°; by the final call the field had settled to a median of 75°. The day verified at 77° against the EGLL observations — drizzle.

GFS landed closest, off by 0.1°. AIFS ran 4° cold.

14 days out the models said 62–79; it hit 77. GFS led (off 0.1°F); AIFS ran 4°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 Mon Sep 14 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 · 2026-08-30 64° 65° 64–65°
14d · 2026-08-31 68° 69° 62° 79° 62–79°
13d · 2026-09-01 65° 61° 59° 76° 59–76°
12d · 2026-09-02 64° 63° 65° 78° 63–78°
11d · 2026-09-03 66° 61° 65° 74° 61–74°
10d · 2026-09-04 68° 63° 64° 72° 63–72°
9d · 2026-09-05 62° 70° 66° 72° 73° 62–73°
8d · 2026-09-06 67° 71° 71° 73° 74° 67–74°
7d · 2026-09-07 71° 72° 72° 74° 77° 71–77°
6d · 2026-09-08 71° 73° 70° 74° 79° 76° 72° 70–79°
5d · 2026-09-09 73° 71° 70° 75° 78° 72° 74° 70–78°
4d · 2026-09-10 73° 74° 76° 76° 78° 76° 75° 73–78°
3d · 2026-09-11 73° 74° 74° 77° 79° 77° 75° 73–79°
2d · 2026-09-12 72° 75° 76° 76° 80° 77° 76° 72–80°
1d · 2026-09-13 72° 73° 75° 77° 78° 76° 74° 72–78°
0d · 2026-09-14 73° 75° 75° 76° 77° 76° 74° 73–77°
actual 77°

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.