Was the forecast right for Chicago on Tue Aug 25?
Chicago, Illinois · daily high temperature in °F · forecasts from each model's archived runs, verified against the MDW observations
4 days out, 7 models put Chicago's Tue Aug 25 high anywhere from 76° to 84°; by the final call the field had settled to a median of 79°. The day verified at 81° against the MDW observations — cloudy.
UKMO landed closest, off by 0.4°. AIFS ran 4° cold.
What every model said, at every lead
Daily-high calls for Tue Aug 25 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 |
|---|---|---|---|---|---|---|---|---|
| 4d · 2026-08-21 | 76° | 77° | 77° | 81° | 80° | 80° | 84° | 76–84° |
| 3d · 2026-08-22 | 77° | 78° | 77° | 78° | 79° | 76° | 80° | 76–80° |
| 2d · 2026-08-23 | 77° | 78° | 81° | 77° | 81° | 79° | 78° | 77–81° |
| 1d · 2026-08-24 | 76° | 77° | 79° | 85° | 79° | 79° | 81° | 76–85° |
| 0d · 2026-08-25 | 77° | 78° | 79° | 84° | 80° | 79° | 81° | 77–84° |
| actual | 81° |
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.