Was the forecast right for London on Sat Sep 12?
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 Sat Sep 12 high anywhere from 16° to 27°; by the final call the field had settled to a median of 22°. The day verified at 24° against the EGLL observations — cloudy.
GEM landed closest, off by 0.1°. AIGFS ran 3° cold.
What every model said, at every lead
Daily-high calls for Sat Sep 12 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-28 | — | 18° | — | — | 17° | — | — | 17–18° |
| 14d · 2026-08-29 | 21° | 16° | 18° | — | 27° | — | — | 16–27° |
| 13d · 2026-08-30 | 22° | 20° | 19° | — | 22° | — | — | 19–22° |
| 12d · 2026-08-31 | 21° | 18° | 18° | — | 22° | — | — | 18–22° |
| 11d · 2026-09-01 | 17° | 22° | 15° | — | 21° | — | — | 15–22° |
| 10d · 2026-09-02 | 20° | 18° | 18° | — | 22° | — | — | 18–22° |
| 9d · 2026-09-03 | 19° | 16° | 19° | 17° | 23° | — | — | 16–23° |
| 8d · 2026-09-04 | 19° | 16° | 20° | 19° | 18° | — | — | 16–20° |
| 7d · 2026-09-05 | 21° | 20° | 20° | 20° | 19° | — | — | 19–21° |
| 6d · 2026-09-06 | 20° | 21° | 23° | 21° | 26° | 21° | 20° | 20–26° |
| 5d · 2026-09-07 | 21° | 21° | 23° | 20° | 24° | 22° | 21° | 20–24° |
| 4d · 2026-09-08 | 21° | 21° | 21° | 20° | 22° | 22° | 21° | 20–22° |
| 3d · 2026-09-09 | 22° | 21° | 21° | 24° | 24° | 22° | 21° | 21–24° |
| 2d · 2026-09-10 | 22° | 22° | 21° | 24° | 24° | 21° | 23° | 21–24° |
| 1d · 2026-09-11 | 22° | 22° | 24° | 24° | 25° | 22° | 23° | 22–25° |
| 0d · 2026-09-12 | 22° | 21° | 22° | 24° | 24° | 22° | 22° | 21–24° |
| 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.