Was the forecast right for Chicago on Wed Sep 9?
Chicago, Illinois · daily high temperature in °F · forecasts from each model's archived runs, verified against the MDW observations
14 days out, 4 models put Chicago's Wed Sep 9 high anywhere from 68° to 83°;by the final call, the day before, the field had settled to a median of 81°. The day verified at 80° against the MDW observations, with 0.04 in of precipitation — showers.
UKMO landed closest, off by 0.7°. AIGFS ran 3° cool.
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 Chicago scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-25 | — | 82° | — | — | 77° | — | — | 77–82° |
| 14d · 2026-08-26 | 83° | 74° | 76° | — | 68° | — | — | 68–83° |
| 13d · 2026-08-27 | 86° | 81° | 84° | — | 91° | — | — | 81–91° |
| 12d · 2026-08-28 | 83° | 83° | 96° | — | 89° | — | — | 83–96° |
| 11d · 2026-08-29 | 79° | 84° | 82° | — | 88° | — | — | 79–88° |
| 10d · 2026-08-30 | 86° | 85° | 82° | — | 78° | — | — | 78–86° |
| 9d · 2026-08-31 | 87° | 91° | 76° | 87° | 89° | — | — | 76–91° |
| 8d · 2026-09-01 | 85° | 81° | 91° | 92° | 85° | — | — | 81–92° |
| 7d · 2026-09-02 | 85° | 91° | 84° | 88° | 97° | — | — | 84–97° |
| 6d · 2026-09-03 | 83° | 83° | 84° | 91° | 91° | 83° | 94° | 83–94° |
| 5d · 2026-09-04 | 84° | 84° | 87° | 86° | 89° | 88° | 93° | 84–93° |
| 4d · 2026-09-05 | 83° | 78° | 87° | 85° | 75° | 80° | 83° | 75–87° |
| 3d · 2026-09-06 | 79° | 76° | 79° | 81° | 82° | 82° | 79° | 76–82° |
| 2d · 2026-09-07 | 79° | 76° | 81° | 80° | 79° | 79° | 80° | 76–81° |
| 1d · 2026-09-08 | 78° | 77° | 82° | 82° | 83° | 78° | 81° | 77–83° |
| actual | 80° |
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 Chicago — 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 MDW observations. The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.