The Spread

Was the forecast right for Houston on Tue Aug 18?

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 Tue Aug 18 high anywhere from 34° to 38°; by the final call the field had settled to a median of 36°. The day verified at 36° against the ECMWF IFS analysis, with 5.1 mm of precipitation — thunderstorms.

GFS landed closest, off by 0.0°. GEM ran 1° hot.

13 days out the models said 34–38; it hit 36. GFS led (off 0.0°C); GEM ran 1°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 Tue Aug 18 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 · 2026-08-03 34° 40° 34–40°
14d · 2026-08-04 36° 37° 40° 36–40°
13d · 2026-08-05 36° 36° 34° 38° 34–38°
12d · 2026-08-06 34° 38° 35° 37° 34–38°
11d · 2026-08-07 35° 37° 35° 38° 35–38°
10d · 2026-08-08 36° 36° 36° 40° 36–40°
9d · 2026-08-09 35° 36° 36° 40° 35–40°
8d · 2026-08-10 36° 37° 36° 38° 38° 36–38°
7d · 2026-08-11 35° 37° 36° 36° 40° 35–40°
6d · 2026-08-12 35° 37° 36° 38° 40° 38° 35–40°
5d · 2026-08-13 36° 36° 36° 38° 39° 35° 36° 35–39°
4d · 2026-08-14 35° 36° 37° 37° 39° 37° 36° 35–39°
3d · 2026-08-15 35° 37° 37° 37° 40° 37° 37° 35–40°
2d · 2026-08-16 35° 37° 36° 38° 39° 36° 37° 35–39°
1d · 2026-08-17 35° 37° 36° 38° 36° 36° 37° 35–38°
0d · 2026-08-18 35° 37° 36° 38° 36° 36° 37° 35–38°
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.