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
14 days out, 4 models put Chicago's Sat Sep 5 high anywhere from 72° to 80°;by the final call, the day before, the field had settled to a median of 81°. The day verified at 83° against the MDW observations — thunderstorms.
ICON landed closest, off by 0.5°. ECMWF ran 4° cool.
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 | — | 75° | — | — | 73° | — | — | 73–75° |
| 14d · 2026-08-22 | 78° | 72° | 78° | — | 80° | — | — | 72–80° |
| 13d · 2026-08-23 | 87° | 78° | 76° | — | 79° | — | — | 76–87° |
| 12d · 2026-08-24 | 86° | 90° | 77° | — | 87° | — | — | 77–90° |
| 11d · 2026-08-25 | 86° | 87° | 89° | — | 86° | — | — | 86–89° |
| 10d · 2026-08-26 | 84° | 88° | 86° | — | 74° | — | — | 74–88° |
| 9d · 2026-08-27 | 80° | 75° | 86° | 75° | 98° | — | — | 75–98° |
| 8d · 2026-08-28 | 75° | 87° | 90° | 85° | 78° | — | — | 75–90° |
| 7d · 2026-08-29 | 82° | 73° | 85° | 85° | 90° | — | — | 73–90° |
| 6d · 2026-08-30 | 78° | 84° | 85° | 80° | 90° | 95° | 91° | 78–95° |
| 5d · 2026-08-31 | 80° | 81° | 88° | 75° | 85° | 90° | 93° | 75–93° |
| 4d · 2026-09-01 | 81° | 83° | 83° | 77° | 87° | 82° | 86° | 77–87° |
| 3d · 2026-09-02 | 82° | 84° | 82° | 84° | 95° | 87° | 91° | 82–95° |
| 2d · 2026-09-03 | 80° | 82° | 84° | 85° | 93° | 87° | 88° | 80–93° |
| 1d · 2026-09-04 | 79° | 81° | 78° | 81° | 84° | 82° | 80° | 78–84° |
| 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. 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.