Was the forecast right for Chicago on Sat Sep 5?
Chicago, Illinois · daily high temperature in °F · forecasts from each model's archived runs, verified against the MDW observations
13 days out, 4 models put Chicago's Sat Sep 5 high anywhere from 73° to 80°; by the final call the field had settled to a median of 81°. The day verified at 83° against the MDW observations — thunderstorms.
AIGFS landed closest, off by 1.1°. UKMO ran 4° cold.
What every model said, at every lead
Daily-high calls for Sat Sep 5 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 · 2026-08-21 | — | 87° | — | — | 86° | — | — | 86–87° |
| 14d · 2026-08-22 | 77° | 87° | — | — | 76° | — | — | 76–87° |
| 13d · 2026-08-23 | 74° | 73° | 74° | — | 80° | — | — | 73–80° |
| 12d · 2026-08-24 | 81° | 80° | 89° | — | 81° | — | — | 80–89° |
| 11d · 2026-08-25 | 82° | 92° | 80° | — | 78° | — | — | 78–92° |
| 10d · 2026-08-26 | 87° | 82° | 90° | — | 84° | — | — | 82–90° |
| 9d · 2026-08-27 | 89° | 85° | 79° | — | 74° | — | — | 74–89° |
| 8d · 2026-08-28 | 82° | 90° | 88° | 81° | 100° | — | — | 81–100° |
| 7d · 2026-08-29 | 76° | 85° | 92° | 85° | 97° | — | — | 76–97° |
| 6d · 2026-08-30 | 80° | 73° | 80° | 87° | 80° | 91° | — | 73–91° |
| 5d · 2026-08-31 | 81° | 78° | 85° | 80° | 85° | 84° | 80° | 78–85° |
| 4d · 2026-09-01 | 82° | 81° | 84° | 80° | 88° | 87° | 92° | 80–92° |
| 3d · 2026-09-02 | 81° | 83° | 84° | 82° | 92° | 86° | 85° | 81–92° |
| 2d · 2026-09-03 | 81° | 83° | 82° | 82° | 88° | 85° | 89° | 81–89° |
| 1d · 2026-09-04 | 80° | 80° | 84° | 84° | 83° | 85° | 80° | 80–85° |
| 0d · 2026-09-05 | 80° | 82° | 80° | 82° | 85° | 81° | 79° | 79–85° |
| actual | 83° |
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. Archive depth varies by city; receipts exist only for dates the archive watched arrive.