Was the forecast right for Chicago on Sun Sep 13?
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 Sun Sep 13 high anywhere from 65° to 91°; by the final call the field had settled to a median of 75°. The day verified at 75° against the MDW observations, with 0.02 in of precipitation — drizzle.
ECMWF landed closest, off by 0.0°. GFS ran 3° hot.
What every model said, at every lead
Daily-high calls for Sun Sep 13 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 · 2026-08-29 | — | 98° | — | — | 84° | — | — | 84–98° |
| 14d · 2026-08-30 | 82° | 74° | — | — | 74° | — | — | 74–82° |
| 13d · 2026-08-31 | 74° | 73° | 65° | — | 91° | — | — | 65–91° |
| 12d · 2026-09-01 | 73° | 75° | 84° | — | 73° | — | — | 73–84° |
| 11d · 2026-09-02 | 79° | 76° | 91° | — | 94° | — | — | 76–94° |
| 10d · 2026-09-03 | 76° | 90° | 75° | — | 86° | — | — | 75–90° |
| 9d · 2026-09-04 | 78° | 62° | 99° | — | 80° | — | — | 62–99° |
| 8d · 2026-09-05 | 74° | 88° | 69° | 68° | 96° | — | — | 68–96° |
| 7d · 2026-09-06 | 71° | 85° | 90° | 74° | 86° | — | — | 71–90° |
| 6d · 2026-09-07 | 75° | 86° | 77° | 78° | 93° | 71° | — | 71–93° |
| 5d · 2026-09-08 | 73° | 73° | 77° | 70° | 80° | 68° | 89° | 68–89° |
| 4d · 2026-09-09 | 73° | 77° | 85° | 76° | 79° | 79° | 78° | 73–85° |
| 3d · 2026-09-10 | 73° | 77° | 75° | 72° | 78° | 78° | 76° | 72–78° |
| 2d · 2026-09-11 | 72° | 77° | 76° | 75° | 79° | 73° | 76° | 72–79° |
| 1d · 2026-09-12 | 72° | 75° | 76° | 77° | 79° | 72° | 76° | 72–79° |
| 0d · 2026-09-13 | 73° | 75° | 75° | 77° | 78° | 73° | 77° | 73–78° |
| actual | 75° |
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.