Was the forecast right for Chicago on Thu Aug 13?
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 Thu Aug 13 high anywhere from 71° to 83°;by the final call, the day before, the field had settled to a median of 77°. The day verified at 79° against the ECMWF IFS analysis, with 0.6 in of precipitation — rain.
UKMO landed closest, off by 0.5°. AIFS ran 5° cool.
What every model said, at every lead
Daily-high calls for Thu Aug 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 · 2026-07-29 | — | 78° | — | — | 79° | — | — | 78–79° |
| 14d · 2026-07-30 | 76° | 80° | 83° | — | 71° | — | — | 71–83° |
| 13d · 2026-07-31 | 84° | 73° | 89° | — | 77° | — | — | 73–89° |
| 12d · 2026-08-01 | 78° | 72° | 82° | — | 92° | — | — | 72–92° |
| 11d · 2026-08-02 | 75° | 74° | 75° | — | 86° | — | — | 74–86° |
| 10d · 2026-08-03 | 77° | 80° | 84° | — | 74° | — | — | 74–84° |
| 9d · 2026-08-04 | 76° | 76° | 80° | 78° | 73° | — | — | 73–80° |
| 8d · 2026-08-05 | 76° | 73° | 82° | 71° | 76° | — | — | 71–82° |
| 7d · 2026-08-06 | 76° | 78° | 79° | 75° | 68° | — | — | 68–79° |
| 6d · 2026-08-07 | 77° | 81° | 78° | 71° | 76° | 81° | 81° | 71–81° |
| 5d · 2026-08-08 | 77° | 76° | 76° | 72° | 70° | 84° | 80° | 70–84° |
| 4d · 2026-08-09 | 75° | 76° | 77° | 73° | 77° | 80° | 76° | 73–80° |
| 3d · 2026-08-10 | 75° | 79° | 74° | 73° | 75° | 78° | 81° | 73–81° |
| 2d · 2026-08-11 | 75° | 76° | 74° | 75° | 74° | 78° | 74° | 74–78° |
| 1d · 2026-08-12 | 74° | 77° | 78° | 75° | 75° | 78° | 79° | 74–79° |
| 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.