The Spread

Was the forecast right for St. Louis on Wed Sep 9?

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

13 days out, 4 models put St. Louis's Wed Sep 9 high anywhere from 19° to 37°; by the final call the field had settled to a median of 36°. The day verified at 34° against the STL observations, with 2.5 mm of precipitation — drizzle.

AIFS landed closest, off by 0.9°. GFS ran 6° hot.

13 days out the models said 19–37; it hit 34. AIFS led (off 0.9°C); GFS ran 6°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 Sep 9 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
15d · 2026-08-25 31° 35° 31–35°
14d · 2026-08-26 27° 25° 22° 22–27°
13d · 2026-08-27 19° 28° 35° 37° 19–37°
12d · 2026-08-28 33° 30° 29° 24° 24–33°
11d · 2026-08-29 32° 38° 36° 33° 32–38°
10d · 2026-08-30 32° 32° 36° 33° 32–36°
9d · 2026-08-31 33° 31° 32° 39° 31–39°
8d · 2026-09-01 35° 39° 39° 37° 40° 35–40°
7d · 2026-09-02 35° 36° 37° 36° 41° 35–41°
6d · 2026-09-03 36° 38° 38° 35° 43° 32° 32–43°
5d · 2026-09-04 35° 37° 38° 36° 43° 33° 34° 33–43°
4d · 2026-09-05 32° 32° 39° 34° 39° 38° 38° 32–39°
3d · 2026-09-06 33° 30° 36° 35° 39° 37° 35° 30–39°
2d · 2026-09-07 34° 32° 36° 33° 39° 35° 36° 32–39°
1d · 2026-09-08 34° 35° 36° 36° 39° 36° 36° 34–39°
0d · 2026-09-09 33° 35° 36° 36° 40° 36° 36° 33–40°
actual 34°

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.