The Spread

Was the forecast right for Houston on Wed Aug 19?

Houston, Texas · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

13 days out, 4 models put Houston's Wed Aug 19 high anywhere from 35° to 38°; by the final call the field had settled to a median of 37°. The day verified at 36° against the ECMWF IFS analysis, with 0.3 mm of precipitation — drizzle.

AIFS landed closest, off by 0.3°. GFS ran 4° hot.

13 days out the models said 35–38; it hit 36. AIFS led (off 0.3°C); GFS ran 4°C 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 Wed Aug 19 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 Houston scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-04 36° 39° 36–39°
14d · 2026-08-05 36° 36° 39° 36–39°
13d · 2026-08-06 35° 37° 36° 38° 35–38°
12d · 2026-08-07 36° 36° 36° 39° 36–39°
11d · 2026-08-08 36° 36° 36° 40° 36–40°
10d · 2026-08-09 36° 36° 36° 41° 36–41°
9d · 2026-08-10 36° 37° 37° 38° 36–38°
8d · 2026-08-11 35° 37° 36° 36° 40° 35–40°
7d · 2026-08-12 36° 37° 35° 38° 41° 35–41°
6d · 2026-08-13 36° 37° 36° 37° 39° 36° 36–39°
5d · 2026-08-14 35° 37° 36° 37° 40° 37° 37° 35–40°
4d · 2026-08-15 35° 38° 38° 36° 41° 37° 37° 35–41°
3d · 2026-08-16 35° 37° 37° 37° 40° 37° 37° 35–40°
2d · 2026-08-17 36° 37° 37° 37° 40° 37° 36° 36–40°
1d · 2026-08-18 36° 37° 37° 37° 37° 37° 36° 36–37°
0d · 2026-08-19 36° 37° 37° 37° 40° 37° 37° 36–40°
actual 36°

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 Houston — 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 ECMWF IFS analysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.