The Spread

Was the forecast right for London on Tue Sep 8?

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

14 days out, 4 models put London's Tue Sep 8 high anywhere from 17° to 27°; by the final call the field had settled to a median of 18°. The day verified at 18° against the EGLL observations, with 14.7 mm of precipitation — showers.

AIFS landed closest, off by 0.2°. AIGFS ran 2° cold.

14 days out the models said 17–27; it hit 18. AIFS led (off 0.2°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 Tue Sep 8 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 · 2026-08-24 24° 25° 24–25°
14d · 2026-08-25 25° 17° 19° 27° 17–27°
13d · 2026-08-26 16° 22° 23° 18° 16–23°
12d · 2026-08-27 17° 22° 16° 19° 16–22°
11d · 2026-08-28 18° 16° 18° 19° 16–19°
10d · 2026-08-29 18° 19° 20° 21° 18–21°
9d · 2026-08-30 17° 18° 20° 20° 23° 17–23°
8d · 2026-08-31 17° 19° 22° 21° 25° 17–25°
7d · 2026-09-01 18° 18° 16° 19° 22° 16–22°
6d · 2026-09-02 19° 16° 18° 20° 19° 22° 18° 16–22°
5d · 2026-09-03 19° 16° 18° 20° 20° 19° 19° 16–20°
4d · 2026-09-04 17° 17° 18° 20° 21° 20° 19° 17–21°
3d · 2026-09-05 16° 18° 20° 19° 20° 21° 19° 16–21°
2d · 2026-09-06 16° 19° 21° 20° 21° 21° 20° 16–21°
1d · 2026-09-07 17° 16° 19° 19° 18° 19° 21° 16–21°
0d · 2026-09-08 18° 16° 17° 17° 18° 19° 18° 16–19°
actual 18°

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.