Was the forecast right for Atlanta on Sun Sep 20?
Atlanta, Georgia · daily high temperature in °F · forecasts from each model's archived runs, verified against the ATL observations
13 days out, 4 models put Atlanta's Sun Sep 20 high anywhere from 82° to 86°; by the final call the field had settled to a median of 88°. The day verified at 89° against the ATL observations — thunderstorms.
ECMWF landed closest, off by 0.9°. UKMO ran 4° cool.
What every model said, at every lead
Daily-high calls for Sun Sep 20 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 Atlanta scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-09-05 | — | 83° | — | — | 94° | — | — | 83–94° |
| 14d · 2026-09-06 | 81° | 71° | — | — | 82° | — | — | 71–82° |
| 13d · 2026-09-07 | 82° | 84° | 83° | — | 86° | — | — | 82–86° |
| 12d · 2026-09-08 | 92° | 87° | 78° | — | 79° | — | — | 78–92° |
| 11d · 2026-09-09 | 84° | 88° | 91° | — | 100° | — | — | 84–100° |
| 10d · 2026-09-10 | 90° | 73° | 74° | — | 70° | — | — | 70–90° |
| 9d · 2026-09-11 | 90° | 81° | 86° | — | 88° | — | — | 81–90° |
| 8d · 2026-09-12 | 90° | 88° | 84° | 93° | 83° | — | — | 83–93° |
| 7d · 2026-09-13 | 89° | 89° | 90° | 90° | 89° | — | — | 89–90° |
| 6d · 2026-09-14 | 89° | 87° | 86° | 90° | 90° | 92° | — | 86–92° |
| 5d · 2026-09-15 | 89° | 90° | 89° | 90° | 90° | 88° | 80° | 80–90° |
| 4d · 2026-09-16 | 86° | 86° | 90° | 86° | 92° | 88° | 88° | 86–92° |
| 3d · 2026-09-17 | 86° | 86° | 88° | 90° | 93° | 84° | 88° | 84–93° |
| 2d · 2026-09-18 | 87° | 87° | 89° | 87° | 91° | 87° | 88° | 87–91° |
| 1d · 2026-09-19 | 86° | 90° | 86° | 81° | 93° | 84° | 88° | 81–93° |
| 0d · 2026-09-20 | 87° | 90° | 90° | 88° | 92° | 86° | 85° | 85–92° |
| actual | 89° |
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 Atlanta — 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 ATL observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.