Was the forecast right for St. Louis on Sun Sep 6?
St. Louis, Missouri · daily high temperature in °F · forecasts from each model's archived runs, verified against the STL observations
12 days out, 4 models put St. Louis's Sun Sep 6 high anywhere from 79° to 98°; by the final call the field had settled to a median of 90°. The day verified at 90° against the STL observations — cloudy.
ECMWF landed closest, off by 0.1°. GEM ran 5° hot.
What every model said, at every lead
Daily-high calls for Sun Sep 6 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 | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 12d · 2026-08-25 | 80° | 79° | 83° | — | 98° | — | — | 79–98° |
| 11d · 2026-08-26 | 84° | 94° | 80° | — | 86° | — | — | 80–94° |
| 10d · 2026-08-27 | 91° | 100° | 106° | — | 94° | — | — | 91–106° |
| 9d · 2026-08-28 | 88° | 99° | 100° | — | 102° | — | — | 88–102° |
| 8d · 2026-08-29 | 82° | 96° | 102° | 99° | 105° | — | — | 82–105° |
| 7d · 2026-08-30 | 87° | 81° | 86° | 96° | 87° | — | — | 81–96° |
| 6d · 2026-08-31 | 88° | 83° | 91° | 86° | 94° | 99° | — | 83–99° |
| 5d · 2026-09-01 | 90° | 94° | 95° | 98° | 101° | 102° | 97° | 90–102° |
| 4d · 2026-09-02 | 90° | 88° | 94° | 97° | 102° | 97° | 96° | 88–102° |
| 3d · 2026-09-03 | 88° | 94° | 92° | 92° | 95° | 91° | 92° | 88–95° |
| 2d · 2026-09-04 | 86° | 91° | 93° | 94° | 96° | 91° | 91° | 86–96° |
| 1d · 2026-09-05 | 87° | 90° | 90° | 94° | 92° | 88° | 90° | 87–94° |
| 0d · 2026-09-06 | 86° | 91° | 90° | 95° | 94° | 89° | 88° | 86–95° |
| actual | 90° |
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.