Was the forecast right for Chicago on Tue Aug 11?
Chicago, Illinois · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Chicago's Tue Aug 11 high anywhere from 72° to 97°;by the final call, the day before, the field had settled to a median of 78°. The day verified at 79° against the ECMWF IFS analysis, with 0.69 in of precipitation — rain.
ECMWF landed closest, off by 0.1°. AIFS ran 3° cool.
What every model said, at every lead
Daily-high calls for Tue Aug 11 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 · 2026-07-27 | — | 83° | — | — | 95° | — | — | 83–95° |
| 14d · 2026-07-28 | 81° | 72° | 92° | — | 97° | — | — | 72–97° |
| 13d · 2026-07-29 | 73° | 74° | 77° | — | 89° | — | — | 73–89° |
| 12d · 2026-07-30 | 83° | 74° | 77° | — | 62° | — | — | 62–83° |
| 11d · 2026-07-31 | 81° | 75° | 82° | — | 77° | — | — | 75–82° |
| 10d · 2026-08-01 | 73° | 75° | 82° | — | 89° | — | — | 73–89° |
| 9d · 2026-08-02 | 78° | 78° | 96° | 72° | 76° | — | — | 72–96° |
| 8d · 2026-08-03 | 77° | 77° | 84° | 74° | 72° | — | — | 72–84° |
| 7d · 2026-08-04 | 76° | 78° | 82° | 77° | 74° | — | — | 74–82° |
| 6d · 2026-08-05 | 74° | 79° | 81° | 72° | 74° | 80° | 85° | 72–85° |
| 5d · 2026-08-06 | 73° | 79° | 80° | 74° | 74° | 77° | 87° | 73–87° |
| 4d · 2026-08-07 | 74° | 73° | 76° | 76° | 73° | 80° | 80° | 73–80° |
| 3d · 2026-08-08 | 74° | 72° | 80° | 74° | 84° | 86° | 76° | 72–86° |
| 2d · 2026-08-09 | 75° | 73° | 78° | 76° | 86° | 79° | 73° | 73–86° |
| 1d · 2026-08-10 | 76° | 78° | 79° | 77° | 77° | 80° | 78° | 76–80° |
| actual | 79° |
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 ECMWF IFS analysis (temperature_2m_max). 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.