Was the forecast right for St. Louis on Thu Sep 10?
St. Louis, Missouri · daily high temperature in °C · forecasts from each model's archived runs, verified against the STL observations
14 days out, 4 models put St. Louis's Thu Sep 10 high anywhere from 29° to 44°;by the final call, the day before, the field had settled to a median of 25°. The day verified at 27° against the STL observations, with 3.8 mm of precipitation — thunderstorms.
GEM landed closest, off by 0.8°. GFS ran 4° cool.
What every model said, at every lead
Daily-high calls for Thu Sep 10 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, labeled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-26 | — | 33° | — | — | 42° | — | — | 33–42° |
| 14d · 2026-08-27 | 35° | 34° | 29° | — | 44° | — | — | 29–44° |
| 13d · 2026-08-28 | 34° | 31° | 36° | — | 33° | — | — | 31–36° |
| 12d · 2026-08-29 | 36° | 32° | 34° | — | 32° | — | — | 32–36° |
| 11d · 2026-08-30 | 34° | 36° | 39° | — | 36° | — | — | 34–39° |
| 10d · 2026-08-31 | 33° | 34° | 33° | — | 34° | — | — | 33–34° |
| 9d · 2026-09-01 | 35° | 31° | 32° | 35° | 28° | — | — | 28–35° |
| 8d · 2026-09-02 | 35° | 34° | 30° | 36° | 41° | — | — | 30–41° |
| 7d · 2026-09-03 | 28° | 30° | 32° | 35° | 44° | — | — | 28–44° |
| 6d · 2026-09-04 | 25° | 23° | 27° | 29° | 31° | 30° | 32° | 23–32° |
| 5d · 2026-09-05 | 26° | 25° | 28° | 30° | 33° | 29° | 31° | 25–33° |
| 4d · 2026-09-06 | 26° | 27° | 28° | 27° | 31° | 27° | 29° | 26–31° |
| 3d · 2026-09-07 | 24° | 25° | 27° | 25° | 26° | 28° | 32° | 24–32° |
| 2d · 2026-09-08 | 25° | 23° | 26° | 24° | 26° | 26° | 30° | 23–30° |
| 1d · 2026-09-09 | 25° | 24° | 25° | 27° | 23° | 25° | 28° | 23–28° |
| actual | 27° |
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. The actual values are the ones in hand when this day was verified, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; verified days exist only for dates the archive watched arrive.