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Which weather model is most accurate in London?

Forecast Highs Lows Rain Model accuracy

London, England · daily high temperature in °C · trailing 30 days, through Fri Oct 16

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 (2026-09-17 to 2026-10-16), for daily high temperature.

One day out, too close to call; at three days, too close to call; at seven days, GEM (Canada) (2.22°C).

The largest standing bias belongs to NOAA AIGFS (AI), which has run cool by about 3.17°C at 3-day lead over this window.

London's full forecast, every model day by day, with the record on this page beside it. Request an invite; it's free during the beta.

The scoreboard

Typical miss (MAE) in °C with the bias in parentheses. Bias is the mean signed error of the predicted daily high — positive means the model ran warm. A model's high is the warmest of its hourly values and the station's is the warmest it got at any moment, so a model's high reads a little cool, and its low a little warm, even on a day it gets every hour right. ECMWF IFS gives a value only every 3 hours (every 6 past day 6), and ECMWF AIFS (AI) and NOAA AIGFS (AI) only every 6, with the hours between filled in, so their highs read cooler still and their lows warmer. In the forecasts scored here GFS also steps to every 3 hours from day 5, ICON and GEM from day 4, and UKMO from day 3, every 6 by day 6. Days = scored days behind the 1-day number.

Model 1-day 3-day 7-day Days
NOAA GFS 1.5° (-1.3°) 2.1° (-1.7°) 2.8° (-2.3°) 29
DWD ICON 1.7° (-1.7°) 2.0° (-2.0°) — 29
UKMO (UK) 1.8° (-1.7°) 2.4° (-2.1°) — 29
ECMWF IFS 2.0° (-2.0°) 2.0° (-2.0°) 2.9° (-2.8°) 29
GEM (Canada) 2.1° (-2.0°) 2.1° (-2.0°) 2.2° (-1.7°) 29
ECMWF AIFS (AI) 2.5° (-2.5°) 2.8° (-2.8°) 2.5° (-2.5°) 29
NOAA AIGFS (AI) 2.9° (-2.9°) 3.3° (-3.2°) 3.5° (-3.5°) 29

Method, honestly

The Spread's London point is the Heathrow station (EGLL), 23 km from downtown, used for both forecasts and verifications. Each forecast is the last one The Spread archived on the day it was made, the forecast the model was showing at the time, not a reconstruction. A day the station did not report is left out. Truth is the thermometer at Heathrow (EGLL) — 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; consensus products such as the NBM, itself a blend of models, are not scored here. 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.

  • Fri Oct 16 14 days out the models said 11–22; it hit 16. UKMO led (off 0.4°C); AIGFS ran 2°C cool.
  • Thu Oct 15 14 days out the models said 13–17; it hit 23. GFS led (off 0.9°C); AIGFS ran 3°C cool.
  • Wed Oct 14 14 days out the models said 15–18; it hit 21. GFS led (off 1.6°C); ICON ran 3°C cool.
  • Tue Oct 13 14 days out the models said 13–16; it hit 21. GFS led (off 0.6°C); AIGFS ran 2°C cool.
  • Mon Oct 12 14 days out the models said 12–18; it hit 18. GEM led (off 0.1°C); AIGFS ran 2°C cool.
  • Sun Oct 11 14 days out the models said 12–19; it hit 17. GFS led (off 0.6°C); AIFS ran 2°C cool.
  • Sat Oct 10 14 days out the models said 16–25; it hit 16. ICON led (off 1.1°C); GFS ran 3°C cool.
  • Fri Oct 9 14 days out the models said 11–25; it hit 21. GEM led (off 2.4°C); UKMO ran 4°C cool.
  • Thu Oct 8 14 days out the models said 14–22; it hit 16. GFS led (off 0.6°C); GEM ran 3°C cool.
  • Wed Oct 7 14 days out the models said 15–21; it hit 15. ICON led (off 0.2°C); GFS ran 2°C warm.
  • Tue Oct 6 14 days out the models said 17–21; it hit 23. UKMO led (off 1.4°C); AIFS ran 4°C cool.
  • Mon Oct 5 14 days out the models said 15–21; it hit 24. GFS led (off 1.5°C); AIFS ran 4°C cool.
  • Sun Oct 4 14 days out the models said 15–20; it hit 24. GFS led (off 2.1°C); AIGFS ran 5°C cool.
  • Sat Oct 3 14 days out the models said 17–20; it hit 21. GEM led (off 0.2°C); AIGFS ran 2°C cool.
  • Fri Oct 2 14 days out the models said 16–21; it hit 22. GFS led (off 1.3°C); UKMO ran 2°C cool.
  • Thu Oct 1 14 days out the models said 16–20; it hit 22. GFS led (off 1.1°C); AIGFS ran 3°C cool.
  • Wed Sep 30 14 days out the models said 12–23; it hit 25. UKMO led (off 1.7°C); GEM ran 4°C cool.
  • Tue Sep 29 14 days out the models said 14–27; it hit 28. UKMO led (off 1.8°C); AIGFS ran 6°C cool.
  • Mon Sep 28 14 days out the models said 16–23; it hit 21. ICON led (off 1.2°C); AIGFS ran 4°C cool.
  • Sun Sep 27 14 days out the models said 15–22; it hit 22. GFS led (off 0.2°C); AIGFS ran 2°C cool.
  • Sat Sep 26 14 days out the models said 16–23; it hit 23. GFS led (off 2.6°C); AIGFS ran 4°C cool.
  • Fri Sep 25 14 days out the models said 14–23; it hit 25. GFS led (off 1.3°C); AIGFS ran 3°C cool.
  • Thu Sep 24 14 days out the models said 19–25; it hit 22. ECMWF led (off 0.4°C); AIGFS ran 2°C cool.
  • Wed Sep 23 14 days out the models said 16–25; it hit 25. GFS led (off 1.0°C); AIGFS ran 3°C cool.
  • Tue Sep 22 14 days out the models said 18–22; it hit 27. AIFS led (off 3.1°C); AIGFS ran 5°C cool.
  • Mon Sep 21 14 days out the models said 17–20; it hit 25. GFS led (off 1.8°C); GEM ran 5°C cool.
  • Sun Sep 20 14 days out the models said 16–29; it hit 22. GFS led (off 1.9°C); AIFS ran 3°C cool.
  • Sat Sep 19 14 days out the models said 18–26; it hit 24. ECMWF led (off 2.0°C); AIFS ran 4°C cool.
  • Fri Sep 18 13 days out the models said 17–24; it hit 20. GFS led (off 0.3°C); GEM ran 1°C cool.
  • Thu Sep 17 14 days out the models said 15–27; it hit 21. ICON led (off 0.2°C); AIGFS ran 2°C cool.
  • Wed Sep 16 14 days out the models said 13–22; it hit 21. ECMWF led (off 1.7°C); UKMO ran 3°C cool.
  • Tue Sep 15 14 days out the models said 17–27; it hit 23. UKMO led (off 0.8°C); AIGFS ran 2°C cool.
  • Mon Sep 14 14 days out the models said 17–26; it hit 25. GEM led (off 0.2°C); AIFS ran 3°C cool.
  • Sun Sep 13 14 days out the models said 16–24; it hit 23. GEM led (off 0.3°C); AIFS ran 2°C cool.
  • Sat Sep 12 14 days out the models said 16–27; it hit 24. GEM led (off 0.3°C); AIFS ran 2°C cool.
  • Fri Sep 11 14 days out the models said 16–23; it hit 21. AIFS led (off 0.0°C); GFS ran 2°C warm.
  • Thu Sep 10 14 days out the models said 17–29; it hit 19. AIFS led (off 0.2°C); ICON ran 2°C warm.
  • Wed Sep 9 14 days out the models said 17–25; it hit 19. GEM led (off 0.1°C); AIGFS ran 2°C cool.
  • Tue Sep 8 14 days out the models said 17–27; it hit 18. GFS led (off 0.4°C); UKMO ran 3°C warm.
  • Mon Sep 7 14 days out the models said 21–24; it hit 24. GEM led (off 0.2°C); AIFS ran 2°C cool.
  • Sun Sep 6 14 days out the models said 20–23; it hit 27. GFS led (off 1.1°C); AIGFS ran 3°C cool.
  • Sat Sep 5 14 days out the models said 17–25; it hit 23. GFS led (off 0.6°C); AIGFS ran 2°C cool.
  • Fri Sep 4 13 days out the models said 19–21; it hit 21. AIGFS led (off 0.1°C); ECMWF ran 1°C cool.
  • Thu Sep 3 12 days out the models said 19–20; it hit 27. GFS led (off 0.3°C); AIFS ran 4°C cool.
  • Wed Sep 2 11 days out the models said 19–21; it hit 21. UKMO led (off 0.7°C); AIFS ran 2°C cool.
  • Tue Sep 1 10 days out the models said 18–21; it hit 23. GFS led (off 0.2°C); ECMWF ran 3°C cool.
  • Mon Aug 31 9 days out the models said 15–23; it hit 24. GEM led (off 1.7°C); GFS ran 5°C cool.
  • Sun Aug 30 8 days out the models said 20–23; it hit 23. GFS led (off 0.6°C); ECMWF ran 2°C cool.
  • Sat Aug 29 7 days out the models said 19–22; it hit 21. UKMO led (off 0.1°C); AIGFS ran 3°C cool.
  • Fri Aug 28 6 days out the models said 17–23; it hit 25. GFS led (off 0.7°C); AIGFS ran 4°C cool.
  • Thu Aug 27 5 days out the models said 21–25; it hit 25. ECMWF led (off 0.1°C); AIFS ran 3°C cool.
  • Wed Aug 26 4 days out the models said 23–27; it hit 27. ICON led (off 0.5°C); AIFS ran 3°C cool.
  • Tue Aug 25 3 days out the models said 22–26; it hit 25. ECMWF led (off 0.1°C); AIGFS ran 2°C cool.
  • Wed Aug 19 8 days out the models said 20–25; it hit 23. UKMO led (off 0.1°C); AIGFS ran 2°C cool.
  • Tue Aug 18 7 days out the models said 20–24; it hit 23. AIFS led (off 0.1°C); GEM ran 2°C warm.
  • Mon Aug 17 6 days out the models said 19–24; it hit 26. ECMWF led (off 0.2°C); AIGFS ran 3°C cool.
  • Sun Aug 16 5 days out the models said 24–27; it hit 25. AIGFS led (off 0.4°C); GFS ran 4°C warm.
  • Sat Aug 15 4 days out the models said 23–28; it hit 27. ICON led (off 0.6°C); GEM ran 4°C warm.
  • Fri Aug 14 3 days out the models said 28–34; it hit 34. GEM led (off 0.3°C); AIGFS ran 2°C cool.

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