Was the forecast right for London on Sat Aug 15?
London, England · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
4 days out, 7 models put London's Sat Aug 15 high anywhere from 73° to 82°;by the final call, the day before, the field had settled to a median of 81°. The day verified at 80° against the ECMWF IFS analysis, with 0.01 in of precipitation — drizzle.
ICON landed closest, off by 1.0°. GEM ran 7° warm.
What every model said, at every lead
Daily-high calls for Sat Aug 15 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 |
|---|---|---|---|---|---|---|---|---|
| 4d · 2026-08-11 | 75° | 75° | 80° | 80° | 82° | 80° | 73° | 73–82° |
| 3d · 2026-08-12 | 77° | 77° | 78° | 84° | 80° | 81° | 76° | 76–84° |
| 2d · 2026-08-13 | 77° | 78° | 79° | 84° | 78° | 80° | 78° | 77–84° |
| 1d · 2026-08-14 | 77° | 78° | 82° | 86° | 83° | 81° | 78° | 77–86° |
| actual | 80° |
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.