Was the forecast right for London on Mon Aug 31?
London, England · daily high temperature in °C · forecasts from each model's archived runs, verified against the EGLL observations
9 days out, 5 models put London's Mon Aug 31 high anywhere from 15° to 23°; by the final call the field had settled to a median of 22°. The day verified at 24° against the EGLL observations — drizzle.
GEM landed closest, off by 1.2°. AIGFS ran 4° cold.
What every model said, at every lead
Daily-high calls for Mon Aug 31 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 |
|---|---|---|---|---|---|---|---|---|
| 9d · 2026-08-22 | 15° | 21° | 20° | 21° | 23° | — | — | 15–23° |
| 8d · 2026-08-23 | 21° | 19° | 21° | 21° | 23° | — | — | 19–23° |
| 7d · 2026-08-24 | 21° | 20° | 21° | 21° | 21° | — | — | 20–21° |
| 6d · 2026-08-25 | 21° | 19° | 20° | 20° | 22° | 22° | 21° | 19–22° |
| 5d · 2026-08-26 | 20° | 20° | 21° | 18° | 21° | 21° | 20° | 18–21° |
| 4d · 2026-08-27 | 20° | 19° | 20° | 21° | 24° | 20° | 21° | 19–24° |
| 3d · 2026-08-28 | 21° | 20° | 21° | 22° | 20° | 23° | 20° | 20–23° |
| 2d · 2026-08-29 | 21° | 19° | 21° | 21° | 20° | 21° | 22° | 19–22° |
| 1d · 2026-08-30 | 21° | 20° | 21° | 22° | 19° | 22° | 21° | 19–22° |
| 0d · 2026-08-31 | 21° | 20° | 22° | 23° | 22° | 23° | 21° | 20–23° |
| actual | 24° |
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.