Was the forecast right for London on Sun Aug 16?
London, England · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
5 days out, 7 models put London's Sun Aug 16 high anywhere from 24° to 27°;by the final call, the day before, the field had settled to a median of 26°. The day verified at 25° against the ECMWF IFS analysis, with 1.0 mm of precipitation — drizzle.
AIGFS landed closest, off by 0.4°. GFS ran 4° warm.
What every model said, at every lead
Daily-high calls for Sun Aug 16 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 |
|---|---|---|---|---|---|---|---|---|
| 5d · 2026-08-11 | 24° | 24° | 25° | 25° | 27° | 25° | 25° | 24–27° |
| 4d · 2026-08-12 | 25° | 22° | 25° | 25° | 23° | 26° | 24° | 22–26° |
| 3d · 2026-08-13 | 25° | 23° | 26° | 25° | 27° | 26° | 24° | 23–27° |
| 2d · 2026-08-14 | 26° | 24° | 27° | 25° | 25° | 25° | 24° | 24–27° |
| 1d · 2026-08-15 | 26° | 24° | 27° | 26° | 28° | 26° | 26° | 24–28° |
| actual | 25° |
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 ECMWF IFS analysis (temperature_2m_max). 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.