Was the forecast right for Chicago on Thu Sep 24?
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 24 high anywhere from 62° to 84°;by the final call, the day before, the field had settled to a median of 69°. The day verified at 69° against the MDW observations — cloudy.
GEM landed closest, off by 0.1°. GFS ran 2° warm.
What every model said, at every lead
Daily-high calls for Thu Sep 24 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 · 2026-09-09 | — | 69° | — | — | 61° | — | — | 61–69° |
| 14d · 2026-09-10 | 66° | 62° | 62° | — | 84° | — | — | 62–84° |
| 13d · 2026-09-11 | 77° | 68° | 64° | — | 76° | — | — | 64–77° |
| 12d · 2026-09-12 | 75° | 76° | 69° | — | 84° | — | — | 69–84° |
| 11d · 2026-09-13 | 68° | 71° | 66° | — | 63° | — | — | 63–71° |
| 10d · 2026-09-14 | 65° | 79° | 70° | — | 69° | — | — | 65–79° |
| 9d · 2026-09-15 | 74° | 78° | 71° | 79° | 75° | — | — | 71–79° |
| 8d · 2026-09-16 | 63° | 66° | 62° | 66° | 80° | — | — | 62–80° |
| 7d · 2026-09-17 | 63° | 64° | 62° | 67° | 66° | — | — | 62–67° |
| 6d · 2026-09-18 | 62° | 64° | 63° | 67° | 65° | 68° | 67° | 62–68° |
| 5d · 2026-09-19 | 64° | 65° | 63° | 68° | 65° | 65° | 65° | 63–68° |
| 4d · 2026-09-20 | 65° | 67° | 65° | 66° | 66° | 66° | 65° | 65–67° |
| 3d · 2026-09-21 | 66° | 67° | 66° | 68° | 68° | 66° | 66° | 66–68° |
| 2d · 2026-09-22 | 66° | 68° | 66° | 67° | 71° | 67° | 68° | 66–71° |
| 1d · 2026-09-23 | 67° | 69° | 67° | 69° | 71° | 69° | 68° | 67–71° |
| actual | 69° |
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.