Which weather model is most accurate in Houston?

Outlook Model accuracy

Houston, Texas · daily high temperature in °C · trailing 30 days · refreshed at most every 6 hours

Every day, The Spread archives what each major weather model predicted for Houston at 1-, 3-, and 7-day leads, then scores those forecasts against the HOU 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, UKMO (UK) (0.82°C); at seven days, too close to call.

The largest standing bias belongs to NOAA GFS, which has run warm by about 1.89°C at 3-day lead over this window.

The Spread's own bias-corrected blend scored a 0.64°C 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 °C 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	0.7° (+0.2°)	1.4° (+0.4°)	—	30
UKMO (UK)	0.8° (+0.5°)	0.8° (+0.2°)	—	30
GEM (Canada)	0.8° (+0.1°)	1.2° (+0.1°)	1.3° (+0.3°)	30
ECMWF AIFS (AI)	1.0° (-0.7°)	1.1° (-0.5°)	0.9° (-0.1°)	30
NOAA AIGFS (AI)	1.1° (+0.8°)	1.3° (+0.9°)	1.6° (+1.6°)	30
ECMWF IFS	1.2° (-0.2°)	1.2° (-0.2°)	0.8° (-0.3°)	30
NOAA GFS	2.0° (+1.9°)	2.0° (+1.9°)	2.2° (+1.9°)	30
NBM (US blend)	1.1° (-0.2°)	1.0° (-0.2°)	0.8° (-0.4°)	30
Blended (bias-corrected)	0.6° (+0.0°)	0.8° (+0.0°)	0.7° (+0.0°)	30

Method, honestly

The Spread's Houston point is the Houston Hobby station (HOU), 16 km 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 HOU 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 two consensus products at the bottom of the table — NBM, which is itself a blend of models, and The Spread's own bias-corrected blend — are shown for comparison, never ranked or named "most accurate" here. 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 34–37; it hit 31. GEM led (off 0.4°C); GFS ran 3°C hot.
Mon Aug 31 9 days out the models said 35–36; it hit 32. AIFS led (off 2.0°C); UKMO ran 4°C hot.
Sun Aug 30 8 days out the models said 36–37; it hit 36. AIGFS led (off 0.2°C); AIFS ran 1°C cold.
Sat Aug 29 7 days out the models said 33–37; it hit 36. AIGFS led (off 0.3°C).
Fri Aug 28 6 days out the models said 36–38; it hit 36. AIGFS led (off 0.8°C); ECMWF ran 3°C cold.
Thu Aug 27 5 days out the models said 34–39; it hit 36. AIGFS led (off 0.2°C); GFS ran 3°C hot.
Wed Aug 26 4 days out the models said 37–39; it hit 37. GEM led (off 0.1°C); GFS ran 3°C hot.
Tue Aug 25 3 days out the models said 36–39; it hit 37. GEM led (off 0.1°C); GFS ran 3°C hot.
Wed Aug 19 13 days out the models said 35–38; it hit 36. AIFS led (off 0.3°C); GFS ran 4°C hot.
Tue Aug 18 13 days out the models said 34–38; it hit 36. GFS led (off 0.0°C); GEM ran 1°C hot.
Mon Aug 17 13 days out the models said 30–41; it hit 37. ECMWF led (off 0.1°C); GFS ran 2°C cold.
Sun Aug 16 13 days out the models said 34–39; it hit 36. AIGFS led (off 0.1°C); AIFS ran 2°C cold.
Sat Aug 15 13 days out the models said 36–38; it hit 36. AIFS led (off 0.2°C); GEM ran 2°C hot.
Fri Aug 14 13 days out the models said 35–37; it hit 34. AIFS led (off 0.0°C); GEM ran 3°C hot.
Thu Aug 13 13 days out the models said 35–41; it hit 36. GFS led (off 0.1°C); GEM ran 2°C hot.
Wed Aug 12 13 days out the models said 35–40; it hit 34. AIFS led (off 0.4°C); AIGFS ran 2°C hot.
Tue Aug 11 13 days out the models said 35–39; it hit 32. ECMWF led (off 0.3°C); AIGFS ran 4°C hot.
Mon Aug 10 13 days out the models said 34–40; it hit 31. AIFS led (off 0.1°C); GEM ran 3°C hot.
Sun Aug 9 13 days out the models said 32–39; it hit 32. ICON led (off 0.2°C); UKMO ran 3°C hot.
Sat Aug 8 12 days out the models said 32–37; it hit 35. GEM led (off 0.3°C); ECMWF ran 3°C cold.
Fri Aug 7 11 days out the models said 30–37; it hit 34. ECMWF led (off 0.1°C); GFS ran 2°C hot.
Thu Aug 6 10 days out the models said 30–39; it hit 33. ECMWF led (off 0.8°C); AIGFS ran 4°C hot.
Wed Aug 5 9 days out the models said 30–40; it hit 35. UKMO led (off 0.0°C).
Tue Aug 4 8 days out the models said 31–39; it hit 36. GEM led (off 0.0°C); ICON ran 2°C cold.
Mon Aug 3 7 days out the models said 32–38; it hit 37. ECMWF led (off 0.2°C); AIFS ran 2°C cold.
Sun Aug 2 6 days out the models said 33–38; it hit 38. UKMO led (off 0.2°C); AIFS ran 3°C cold.
Sat Aug 1 5 days out the models said 35–41; it hit 36. GFS led (off 0.1°C); UKMO ran 2°C hot.
Fri Jul 31 4 days out the models said 34–39; it hit 36. GEM led (off 0.0°C); AIFS ran 2°C cold.
Thu Jul 30 3 days out the models said 34–39; it hit 36. ECMWF led (off 0.3°C); AIFS ran 2°C cold.

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The Spread — the forecast spread — is in closed beta. These verification pages are public while the rest is gated.