The Spread

Was the forecast right for St. Louis on Mon Aug 31?

St. Louis, Missouri · daily high temperature in °C · forecasts from each model's archived runs, verified against the STL observations

6 days out, 6 models put St. Louis's Mon Aug 31 high anywhere from 27° to 39°; by the final call the field had settled to a median of 37°. The day verified at 37° against the STL observations — cloudy.

ECMWF landed closest, off by 0.1°. GEM ran 2° hot.

6 days out the models said 27–39; it hit 37. ECMWF led (off 0.1°C); GEM ran 2°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 Mon Aug 31 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 St. Louis scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
6d · 2026-08-25 34° 34° 36° 33° 39° 27° — 27–39°
5d · 2026-08-26 35° 36° 37° 35° 39° 36° 34° 34–39°
4d · 2026-08-27 36° 34° 38° 34° 40° 36° 33° 33–40°
3d · 2026-08-28 36° 34° 38° 35° 41° 36° 34° 34–41°
2d · 2026-08-29 36° 35° 38° 35° 41° 36° 36° 35–41°
1d · 2026-08-30 36° 36° 37° 38° 39° 37° 36° 36–39°
0d · 2026-08-31 36° 37° 37° 39° 38° 37° 36° 36–39°
actual 37°

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 St. Louis — 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 STL observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.