The Spread

Was the forecast right for London on Thu Sep 10?

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 Thu Sep 10 high anywhere from 62° to 84°; by the final call the field had settled to a median of 67°. The day verified at 66° against the EGLL observations, with 0.04 in of precipitation — drizzle.

ECMWF landed closest, off by 0.5°. GFS ran 4° hot.

14 days out the models said 62–84; it hit 66. ECMWF led (off 0.5°F); GFS ran 4°F hot.
The shareable card for this receipt — what this page looks like pasted into a thread.

What every model said, at every lead

Daily-high calls for Thu Sep 10 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 AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-26 63° 68° 63–68°
14d · 2026-08-27 62° 74° 63° 84° 62–84°
13d · 2026-08-28 70° 63° 63° 63° 63–70°
12d · 2026-08-29 66° 69° 70° 60° 60–70°
11d · 2026-08-30 69° 67° 70° 56° 56–70°
10d · 2026-08-31 66° 63° 70° 69° 63–70°
9d · 2026-09-01 64° 65° 62° 67° 63° 62–67°
8d · 2026-09-02 66° 63° 63° 70° 64° 63–70°
7d · 2026-09-03 65° 65° 64° 68° 76° 64–76°
6d · 2026-09-04 65° 65° 63° 68° 64° 64° 63–68°
5d · 2026-09-05 66° 66° 63° 68° 73° 68° 68° 63–73°
4d · 2026-09-06 67° 68° 72° 71° 70° 68° 67° 67–72°
3d · 2026-09-07 67° 67° 66° 70° 70° 69° 69° 66–70°
2d · 2026-09-08 66° 67° 65° 68° 68° 69° 67° 65–69°
1d · 2026-09-09 67° 67° 66° 68° 69° 69° 68° 66–69°
0d · 2026-09-10 67° 68° 67° 68° 70° 67° 67° 67–70°
actual 66°

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.