The Spread

Was the forecast right for London on Sat Aug 29?

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

7 days out, 5 models put London's Sat Aug 29 high anywhere from 19° to 22°; by the final call the field had settled to a median of 20°. The day verified at 21° against the EGLL observations, with 3.6 mm of precipitation — showers.

UKMO landed closest, off by 0.1°. AIGFS ran 2° cold.

7 days out the models said 19–22; it hit 21. UKMO led (off 0.1°C); AIGFS ran 2°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 Sat Aug 29 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
7d · 2026-08-22 21° 21° 20° 19° 22° 19–22°
6d · 2026-08-23 21° 21° 21° 21° 25° 22° 21° 21–25°
5d · 2026-08-24 22° 22° 19° 22° 18° 23° 23° 18–23°
4d · 2026-08-25 20° 22° 20° 24° 26° 20° 21° 20–26°
3d · 2026-08-26 20° 20° 20° 20° 22° 21° 22° 20–22°
2d · 2026-08-27 19° 19° 20° 21° 22° 21° 22° 19–22°
1d · 2026-08-28 18° 18° 19° 19° 20° 20° 21° 18–21°
0d · 2026-08-29 19° 19° 20° 21° 20° 21° 21° 19–21°
actual 21°

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.