The Spread

Was the forecast right for London on Wed Aug 26?

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

4 days out, 7 models put London's Wed Aug 26 high anywhere from 73° to 81°; by the final call the field had settled to a median of 79°. The day verified at 81° against the EGLL observations, with 0.02 in of precipitation — thunderstorms.

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

4 days out the models said 73–81; it hit 81. GEM 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 Wed Aug 26 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
4d · 2026-08-22 74° 78° 74° 73° 81° 81° 75° 73–81°
3d · 2026-08-23 76° 77° 78° 75° 81° 78° 77° 75–81°
2d · 2026-08-24 75° 78° 76° 80° 83° 78° 72° 72–83°
1d · 2026-08-25 76° 78° 80° 79° 83° 80° 78° 76–83°
0d · 2026-08-26 77° 79° 78° 80° 82° 79° 80° 77–82°
actual 81°

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.