The Spread

Was the forecast right for London on Sat Sep 5?

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 Sat Sep 5 high anywhere from 63° to 76°; by the final call the field had settled to a median of 71°. The day verified at 73° against the EGLL observations — cloudy.

GFS landed closest, off by 0.5°. AIGFS ran 3° cold.

14 days out the models said 63–76; it hit 73. GFS led (off 0.5°F); AIGFS ran 3°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 Sat Sep 5 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
14d · 2026-08-22 76° 63° 69° 70° 63–76°
13d · 2026-08-23 75° 73° 77° 65° 65–77°
12d · 2026-08-24 73° 67° 68° 67° 67–73°
11d · 2026-08-25 67° 66° 80° 67° 66–80°
10d · 2026-08-26 79° 65° 68° 76° 65–79°
9d · 2026-08-27 69° 67° 73° 79° 66° 66–79°
8d · 2026-08-28 71° 72° 65° 78° 69° 65–78°
7d · 2026-08-29 73° 70° 62° 71° 76° 62–76°
6d · 2026-08-30 74° 70° 70° 64° 70° 67° 70° 64–74°
5d · 2026-08-31 72° 72° 70° 74° 72° 72° 72° 70–74°
4d · 2026-09-01 72° 70° 68° 72° 71° 70° 70° 68–72°
3d · 2026-09-02 71° 70° 72° 73° 74° 71° 71° 70–74°
2d · 2026-09-03 71° 70° 71° 73° 73° 70° 70° 70–73°
1d · 2026-09-04 70° 70° 71° 72° 72° 71° 72° 70–72°
0d · 2026-09-05 71° 70° 72° 71° 73° 71° 70° 70–73°
actual 73°

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.