Was the forecast right for London on Tue Sep 1?
London, England · daily high temperature in °F · forecasts from each model's archived runs, verified against the EGLL observations
10 days out, 4 models put London's Tue Sep 1 high anywhere from 65° to 70°; by the final call the field had settled to a median of 71°. The day verified at 73° against the EGLL observations — cloudy.
GFS landed closest, off by 0.2°. ECMWF ran 4° cold.
What every model said, at every lead
Daily-high calls for Tue Sep 1 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 |
|---|---|---|---|---|---|---|---|---|
| 10d · 2026-08-22 | 65° | 69° | 67° | — | 70° | — | — | 65–70° |
| 9d · 2026-08-23 | 68° | 68° | 69° | 68° | 68° | — | — | 68–69° |
| 8d · 2026-08-24 | 66° | 71° | 69° | 70° | 70° | — | — | 66–71° |
| 7d · 2026-08-25 | 68° | 72° | 68° | 71° | 72° | — | — | 68–72° |
| 6d · 2026-08-26 | 67° | 69° | 67° | 69° | 69° | 71° | 69° | 67–71° |
| 5d · 2026-08-27 | 70° | 70° | 66° | 71° | 72° | 71° | 70° | 66–72° |
| 4d · 2026-08-28 | 70° | 70° | 70° | 70° | 72° | 72° | 69° | 69–72° |
| 3d · 2026-08-29 | 70° | 69° | 69° | 72° | 73° | 71° | 71° | 69–73° |
| 2d · 2026-08-30 | 70° | 69° | 69° | 71° | 74° | 72° | 70° | 69–74° |
| 1d · 2026-08-31 | 70° | 69° | 68° | 71° | 73° | 73° | 70° | 68–73° |
| 0d · 2026-09-01 | 71° | 70° | 69° | 72° | 74° | 71° | 71° | 69–74° |
| actual | 73° |
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.