Which weather model is most accurate in Houston?
Houston, Texas · daily high temperature · 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 ERA5 reanalysis once the day has happened. This page covers the trailing 30 days (2026-07-06 to 2026-08-05), for daily high temperature.
One day out, NOAA AIGFS (AI) has been most accurate (typical miss 1.51°F); at three days, NOAA AIGFS (AI) (2.01°F); at seven days, ECMWF AIFS (AI) (2.79°F).
The largest standing bias belongs to NOAA GFS, which has run warm by about 5.33°F at 3-day lead over this window.
The Spread's own bias-corrected blend scored a 1.27°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) 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 |
|---|---|---|---|---|
| NOAA AIGFS (AI) | 1.5° (-0.7°) | 2.0° (-1.3°) | 3.2° (-2.1°) | 30 |
| ECMWF IFS | 1.8° (-0.5°) | 2.4° (+0.1°) | 3.1° (+0.6°) | 30 |
| NOAA GFS | 1.9° (+0.4°) | 5.8° (+5.3°) | 6.8° (+6.7°) | 30 |
| ECMWF AIFS (AI) | 2.0° (-1.5°) | 2.1° (-1.2°) | 2.8° (-1.7°) | 30 |
| DWD ICON | 2.0° (+1.0°) | 2.6° (+1.7°) | — | 30 |
| GEM (Canada) | 2.5° (+1.9°) | 2.5° (+1.4°) | 3.0° (+1.5°) | 30 |
| UKMO (UK) | 3.1° (+2.9°) | 3.6° (+3.5°) | — | 30 |
| NBM (US blend) | 1.5° (-0.1°) | 2.1° (+0.8°) | 3.4° (+1.2°) | 30 |
| Blended (bias-corrected) | 1.3° (-0.0°) | 1.5° (+0.0°) | 2.4° (-0.0°) | 30 |
Method, honestly
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 ERA5 reanalysis daily highs. 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.
- Sun Aug 2 6 days out the models said 91–100; it hit 100. UKMO led (off 0.3°); AIFS ran 6° cold.
- Sat Aug 1 5 days out the models said 94–105; it hit 97. GFS led (off 0.1°); UKMO ran 3° hot.
- Fri Jul 31 4 days out the models said 94–102; it hit 98. GEM led (off 0.0°); AIFS ran 3° cold.
- Thu Jul 30 3 days out the models said 93–103; it hit 97. ECMWF led (off 0.5°); AIFS ran 3° cold.
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The Spread — the forecast spread — is in closed beta. These verification pages are public while the rest is gated.