Was the forecast right for Chicago on Thu Sep 10?
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 Thu Sep 10 high anywhere from 76° to 97°;by the final call, the day before, the field had settled to a median of 77°. The day verified at 76° against the MDW observations — cloudy.
ECMWF landed closest, off by 0.2°. GFS ran 5° warm.
What every model said, at every lead
Daily-high calls for Thu Sep 10 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, labeled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-26 | — | 80° | — | — | 85° | — | — | 80–85° |
| 14d · 2026-08-27 | 92° | 84° | 76° | — | 97° | — | — | 76–97° |
| 13d · 2026-08-28 | 88° | 77° | 96° | — | 90° | — | — | 77–96° |
| 12d · 2026-08-29 | 89° | 88° | 82° | — | 72° | — | — | 72–89° |
| 11d · 2026-08-30 | 85° | 93° | 72° | — | 84° | — | — | 72–93° |
| 10d · 2026-08-31 | 88° | 92° | 81° | — | 86° | — | — | 81–92° |
| 9d · 2026-09-01 | 83° | 68° | 80° | 93° | 76° | — | — | 68–93° |
| 8d · 2026-09-02 | 81° | 76° | 73° | 84° | 82° | — | — | 73–84° |
| 7d · 2026-09-03 | 75° | 80° | 78° | 89° | 84° | — | — | 75–89° |
| 6d · 2026-09-04 | 76° | 75° | 81° | 75° | 80° | 77° | 80° | 75–81° |
| 5d · 2026-09-05 | 74° | 77° | 82° | 78° | 86° | 77° | 75° | 74–86° |
| 4d · 2026-09-06 | 75° | 75° | 77° | 74° | 77° | 76° | 77° | 74–77° |
| 3d · 2026-09-07 | 76° | 76° | 79° | 76° | 78° | 78° | 80° | 76–80° |
| 2d · 2026-09-08 | 75° | 74° | 76° | 77° | 79° | 77° | 77° | 74–79° |
| 1d · 2026-09-09 | 75° | 75° | 76° | 80° | 81° | 79° | 77° | 75–81° |
| actual | 76° |
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 day was verified, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; verified days exist only for dates the archive watched arrive.