Was the forecast right for Chicago on Tue Sep 8?
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 Tue Sep 8 high anywhere from 74° to 87°;by the final call, the day before, the field had settled to a median of 84°. The day verified at 87° against the MDW observations — cloudy.
GFS landed closest, off by 0.5°. AIFS ran 6° cool.
What every model said, at every lead
Daily-high calls for Tue Sep 8 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 · 2026-08-24 | — | 76° | — | — | 85° | — | — | 76–85° |
| 14d · 2026-08-25 | 77° | 78° | 74° | — | 87° | — | — | 74–87° |
| 13d · 2026-08-26 | 78° | 77° | 82° | — | 75° | — | — | 75–82° |
| 12d · 2026-08-27 | 76° | 79° | 94° | — | 90° | — | — | 76–94° |
| 11d · 2026-08-28 | 78° | 74° | 92° | — | 95° | — | — | 74–95° |
| 10d · 2026-08-29 | 76° | 80° | 91° | — | 85° | — | — | 76–91° |
| 9d · 2026-08-30 | 81° | 75° | 92° | 78° | 74° | — | — | 74–92° |
| 8d · 2026-08-31 | 81° | 87° | 69° | 83° | 76° | — | — | 69–87° |
| 7d · 2026-09-01 | 82° | 84° | 85° | 88° | 81° | — | — | 81–88° |
| 6d · 2026-09-02 | 81° | 92° | 82° | 84° | 94° | 92° | 83° | 81–94° |
| 5d · 2026-09-03 | 81° | 85° | 84° | 85° | 89° | 89° | 88° | 81–89° |
| 4d · 2026-09-04 | 82° | 86° | 86° | 83° | 88° | 85° | 93° | 82–93° |
| 3d · 2026-09-05 | 82° | 84° | 84° | 83° | 87° | 85° | 88° | 82–88° |
| 2d · 2026-09-06 | 82° | 83° | 85° | 84° | 85° | 84° | 87° | 82–87° |
| 1d · 2026-09-07 | 81° | 82° | 84° | 91° | 88° | 84° | 85° | 81–91° |
| actual | 87° |
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.