Was the forecast right for Chicago on Sat Aug 8?
Chicago, Illinois · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
13 days out, 4 models put Chicago's Sat Aug 8 high anywhere from 82° to 95°;by the final call, the day before, the field had settled to a median of 80°. The day verified at 80° against the ECMWF IFS analysis — drizzle.
AIGFS landed closest, off by 0.6°. UKMO ran 3° warm.
What every model said, at every lead
Daily-high calls for Sat Aug 8 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 |
|---|---|---|---|---|---|---|---|---|
| 13d · 2026-07-26 | 86° | 82° | 95° | — | 82° | — | — | 82–95° |
| 12d · 2026-07-27 | 90° | 81° | 83° | — | 74° | — | — | 74–90° |
| 11d · 2026-07-28 | 76° | 78° | 93° | — | 83° | — | — | 76–93° |
| 10d · 2026-07-29 | 86° | 85° | 92° | — | 79° | — | — | 79–92° |
| 9d · 2026-07-30 | 82° | 83° | 90° | 71° | 78° | — | — | 71–90° |
| 8d · 2026-07-31 | 83° | 78° | 79° | 85° | 92° | — | — | 78–92° |
| 7d · 2026-08-01 | 83° | 81° | 83° | 79° | 85° | — | — | 79–85° |
| 6d · 2026-08-02 | 84° | 85° | 86° | 82° | 87° | 86° | 86° | 82–87° |
| 5d · 2026-08-03 | 82° | 86° | 87° | 88° | 83° | 87° | 90° | 82–90° |
| 4d · 2026-08-04 | 82° | 86° | 79° | 82° | 89° | 87° | 81° | 79–89° |
| 3d · 2026-08-05 | 81° | 84° | 82° | 81° | 83° | 87° | 84° | 81–87° |
| 2d · 2026-08-06 | 80° | 82° | 82° | 82° | 80° | 84° | 84° | 80–84° |
| 1d · 2026-08-07 | 79° | 81° | 79° | 80° | 78° | 82° | 84° | 78–84° |
| actual | 80° |
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.