The Spread

Was the forecast right for London on Thu Aug 27?

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

5 days out, 7 models put London's Thu Aug 27 high anywhere from 21° to 25°; by the final call the field had settled to a median of 23°. The day verified at 25° against the EGLL observations, with 4.3 mm of precipitation — thunderstorms.

ICON landed closest, off by 0.1°. AIGFS ran 4° cold.

5 days out the models said 21–25; it hit 25. ICON led (off 0.1°C); AIGFS ran 4°C 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 Thu Aug 27 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
5d · 2026-08-22 23° 24° 23° 21° 25° 24° 23° 21–25°
4d · 2026-08-23 24° 24° 24° 22° 26° 22° 23° 22–26°
3d · 2026-08-24 24° 25° 23° 23° 26° 25° 24° 23–26°
2d · 2026-08-25 23° 24° 23° 22° 26° 24° 23° 22–26°
1d · 2026-08-26 22° 22° 25° 23° 23° 25° 24° 22–25°
0d · 2026-08-27 22° 21° 23° 24° 23° 25° 23° 21–25°
actual 25°

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.