Was the forecast right for London on Thu Sep 3?
London, England · daily high temperature in °F · forecasts from each model's archived runs, verified against the EGLL observations
12 days out, 4 models put London's Thu Sep 3 high anywhere from 66° to 69°;by the final call, the day before, the field had settled to a median of 77°. The day verified at 81° against the EGLL observations — drizzle.
GFS landed closest, off by 0.5°. AIFS ran 8° cool.
What every model said, at every lead
Daily-high calls for Thu Sep 3 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 |
|---|---|---|---|---|---|---|---|---|
| 12d · 2026-08-22 | 68° | 69° | 66° | — | 66° | — | — | 66–69° |
| 11d · 2026-08-23 | 67° | 69° | 69° | — | 73° | — | — | 67–73° |
| 10d · 2026-08-24 | 71° | 65° | 70° | — | 69° | — | — | 65–71° |
| 9d · 2026-08-25 | 73° | 68° | 72° | 68° | 69° | — | — | 68–73° |
| 8d · 2026-08-26 | 66° | 67° | 73° | 68° | 74° | — | — | 66–74° |
| 7d · 2026-08-27 | 74° | 72° | 71° | 70° | 70° | — | — | 70–74° |
| 6d · 2026-08-28 | 73° | 70° | 71° | 73° | 80° | 70° | 70° | 70–80° |
| 5d · 2026-08-29 | 73° | 70° | 72° | 73° | 73° | 72° | 74° | 70–74° |
| 4d · 2026-08-30 | 73° | 74° | 75° | 76° | 79° | 75° | 75° | 73–79° |
| 3d · 2026-08-31 | 72° | 73° | 76° | 78° | 76° | 78° | 71° | 71–78° |
| 2d · 2026-09-01 | 72° | 73° | 76° | 79° | 78° | 75° | 73° | 72–79° |
| 1d · 2026-09-02 | 73° | 74° | 77° | 77° | 80° | 79° | 79° | 73–80° |
| actual | 81° |
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. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.