Was the forecast right for London on Wed Sep 23?
London, England · daily high temperature in °F · forecasts from each model's archived runs, verified against the EGLL observations
14 days out, 4 models put London's Wed Sep 23 high anywhere from 61° to 78°;by the final call, the day before, the field had settled to a median of 73°. The day verified at 76° against the EGLL observations — cloudy.
GFS landed closest, off by 1.8°. AIGFS ran 5° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 23 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 · 2026-09-08 | — | 66° | — | — | 63° | — | — | 63–66° |
| 14d · 2026-09-09 | 71° | 78° | 61° | — | 69° | — | — | 61–78° |
| 13d · 2026-09-10 | 70° | 66° | 73° | — | 63° | — | — | 63–73° |
| 12d · 2026-09-11 | 70° | 64° | 60° | — | 72° | — | — | 60–72° |
| 11d · 2026-09-12 | 62° | 63° | 64° | — | 76° | — | — | 62–76° |
| 10d · 2026-09-13 | 67° | 62° | 69° | — | 64° | — | — | 62–69° |
| 9d · 2026-09-14 | 67° | 64° | 78° | 69° | 80° | — | — | 64–80° |
| 8d · 2026-09-15 | 69° | 65° | 75° | 68° | 73° | — | — | 65–75° |
| 7d · 2026-09-16 | 70° | 71° | 70° | 70° | 74° | — | — | 70–74° |
| 6d · 2026-09-17 | 70° | 69° | 68° | 73° | 71° | 74° | 66° | 66–74° |
| 5d · 2026-09-18 | 70° | 69° | 76° | 72° | 75° | 66° | 68° | 66–76° |
| 4d · 2026-09-19 | 68° | 72° | 66° | 72° | 75° | 73° | 67° | 66–75° |
| 3d · 2026-09-20 | 71° | 71° | 71° | 71° | 75° | 73° | 71° | 71–75° |
| 2d · 2026-09-21 | 73° | 70° | 74° | 71° | 74° | 71° | 69° | 69–74° |
| 1d · 2026-09-22 | 73° | 72° | 74° | 74° | 75° | 73° | 72° | 72–75° |
| actual | 76° |
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.