Was the forecast right for London on Wed Aug 26?
London, England · daily high temperature in °C · 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 23° to 27°; by the final call the field had settled to a median of 26°. The day verified at 27° against the EGLL observations, with 0.5 mm of precipitation — thunderstorms.
GEM landed closest, off by 0.1°. AIFS ran 2° cold.
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 | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 4d · 2026-08-22 | 23° | 25° | 24° | 23° | 27° | 27° | 24° | 23–27° |
| 3d · 2026-08-23 | 24° | 25° | 25° | 24° | 27° | 25° | 25° | 24–27° |
| 2d · 2026-08-24 | 24° | 25° | 24° | 27° | 28° | 25° | 22° | 22–28° |
| 1d · 2026-08-25 | 24° | 26° | 26° | 26° | 28° | 26° | 26° | 24–28° |
| 0d · 2026-08-26 | 25° | 26° | 26° | 27° | 28° | 26° | 26° | 25–28° |
| actual | 27° |
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.