Was the forecast right for St. Louis on Sun Sep 20?
St. Louis, Missouri · daily high temperature in °F · forecasts from each model's archived runs, verified against the STL observations
13 days out, 4 models put St. Louis's Sun Sep 20 high anywhere from 70° to 82°; by the final call the field had settled to a median of 88°. The day verified at 92° against the STL observations, with 0.73 in of precipitation — showers.
GEM landed closest, off by 0.6°. AIFS ran 6° cool.
What every model said, at every lead
Daily-high calls for Sun Sep 20 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-09-05 | — | 76° | — | — | 77° | — | — | 76–77° |
| 14d · 2026-09-06 | 81° | 71° | — | — | 86° | — | — | 71–86° |
| 13d · 2026-09-07 | 70° | 72° | 82° | — | 74° | — | — | 70–82° |
| 12d · 2026-09-08 | 82° | 70° | 76° | — | 80° | — | — | 70–82° |
| 11d · 2026-09-09 | 74° | 72° | 90° | — | 98° | — | — | 72–98° |
| 10d · 2026-09-10 | 73° | 76° | 76° | — | 82° | — | — | 73–82° |
| 9d · 2026-09-11 | 72° | 77° | 74° | — | 76° | — | — | 72–77° |
| 8d · 2026-09-12 | 73° | 74° | 76° | 79° | 75° | — | — | 73–79° |
| 7d · 2026-09-13 | 84° | 80° | 99° | 92° | 82° | — | — | 80–99° |
| 6d · 2026-09-14 | 83° | 93° | 98° | 95° | 98° | 98° | — | 83–98° |
| 5d · 2026-09-15 | 83° | 92° | 99° | 83° | 97° | 93° | 86° | 83–99° |
| 4d · 2026-09-16 | 91° | 88° | 95° | 87° | 97° | 91° | 86° | 86–97° |
| 3d · 2026-09-17 | 88° | 89° | 93° | 90° | 96° | 84° | 83° | 83–96° |
| 2d · 2026-09-18 | 89° | 89° | 91° | 94° | 95° | 85° | 86° | 85–95° |
| 1d · 2026-09-19 | 90° | 90° | 92° | 91° | 94° | 90° | 86° | 86–94° |
| 0d · 2026-09-20 | 86° | 91° | 88° | 93° | 95° | 87° | 88° | 86–95° |
| actual | 92° |
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.