Which weather model is most accurate in London?
London, England · daily high temperature in °F · trailing 30 days · refreshed at most every 6 hours
Every day, The Spread archives what each major weather model predicted for London at 1-, 3-, and 7-day leads, then scores those forecasts against the EGLL observations once the day has happened. This page covers the trailing 30 days (2026-08-04 to 2026-09-02), for daily high temperature.
One day out, too close to call; at three days, too close to call; at seven days, too close to call.
The largest standing bias belongs to NOAA AIGFS (AI), which has run cool by about 4.14°F at 3-day lead over this window.
The Spread's own bias-corrected blend scored a 1.26°F typical miss at one day. Its corrections come from the same window it is scored on (in-sample), so read it as a ceiling, not a promise.
The scoreboard
Typical miss (MAE) in °F with the signed bias in parentheses — positive bias means the model ran warm. Days = scored days behind the 1-day number.
| Model | 1-day | 3-day | 7-day | Days |
|---|---|---|---|---|
| DWD ICON | 1.5° (-0.8°) | 2.0° (-1.4°) | — | 30 |
| NOAA GFS | 1.7° (+0.1°) | 1.9° (+0.2°) | 4.6° (-0.7°) | 30 |
| ECMWF IFS | 1.9° (-1.6°) | 2.5° (-2.1°) | 5.3° (-4.5°) | 30 |
| UKMO (UK) | 1.9° (-1.2°) | 2.7° (-2.6°) | — | 30 |
| GEM (Canada) | 2.0° (-0.9°) | 2.8° (-1.6°) | 4.3° (-3.0°) | 30 |
| ECMWF AIFS (AI) | 2.6° (-2.5°) | 3.2° (-3.1°) | 4.9° (-3.8°) | 30 |
| NOAA AIGFS (AI) | 2.9° (-2.9°) | 4.2° (-4.1°) | 5.5° (-4.8°) | 30 |
| Blended (bias-corrected) | 1.3° (+0.0°) | 1.3° (+0.0°) | 3.0° (+0.0°) | 30 |
Method, honestly
The Spread's London point is the London Heathrow station (EGLL), 14 mi from downtown, used for both forecasts and verifications. Forecasts come from each model's actual archived runs via Open-Meteo's Previous Runs API — what the model said at the time, not a reconstruction. Truth is EGLL observations — the station's own daily highs, a thermometer rather than a grid, and no correction applies: the thermometer is the truth outright. Rankings cover the models themselves; the consensus row at the bottom of the table — The Spread's own bias-corrected blend — is shown for comparison, never ranked or named "most accurate" here. NBM, the US official blend these pages benchmark against elsewhere, covers the United States only and has no row for this city. The blend's corrections come from the same trailing window it is scored on (in-sample), so treat its score as a ceiling. A rolling 30-day window means these numbers move — that is the point.
Receipts — was the forecast right?
One page per settled date: what every model said as the day approached, what happened, and who was closest.
- Tue Sep 1 10 days out the models said 65–70; it hit 73. GFS led (off 0.2°F); ECMWF ran 4°F cold.
- Mon Aug 31 9 days out the models said 60–74; it hit 75. GEM led (off 2.2°F); AIGFS ran 8°F cold.
- Sun Aug 30 8 days out the models said 67–73; it hit 73. GFS led (off 0.2°F); UKMO ran 4°F cold.
- Sat Aug 29 7 days out the models said 66–71; it hit 70. UKMO led (off 0.1°F); AIGFS ran 4°F cold.
- Fri Aug 28 6 days out the models said 63–73; it hit 77. GFS led (off 0.1°F); UKMO ran 4°F cold.
- Thu Aug 27 5 days out the models said 71–77; it hit 77. ICON led (off 0.1°F); AIGFS ran 7°F cold.
- Wed Aug 26 4 days out the models said 73–81; it hit 81. GEM led (off 0.1°F); AIFS ran 4°F cold.
- Tue Aug 25 3 days out the models said 72–80; it hit 77. ICON led (off 0.0°F).
- Wed Aug 19 8 days out the models said 68–78; it hit 74. UKMO led (off 0.2°F); AIFS ran 3°F cold.
- Tue Aug 18 7 days out the models said 68–76; it hit 74. AIGFS led (off 0.8°F); GFS ran 7°F hot.
- Mon Aug 17 6 days out the models said 66–75; it hit 78. GFS led (off 0.1°F).
- Sun Aug 16 5 days out the models said 75–80; it hit 76. AIFS led (off 0.1°F); ECMWF ran 4°F cold.
- Sat Aug 15 4 days out the models said 73–82; it hit 80. ICON led (off 1.0°F); GEM ran 6°F hot.
- Fri Aug 14 3 days out the models said 82–92; it hit 93. UKMO led (off 0.6°F); AIFS ran 3°F cold.
Other cities
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The Spread — the forecast spread — is in closed beta. These verification pages are public while the rest is gated.