Was the forecast right for Atlanta on Sun Sep 20?
Atlanta, Georgia · daily high temperature in °C · 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 28° to 30°; by the final call the field had settled to a median of 31°. The day verified at 32° against the ATL observations — thunderstorms.
ECMWF landed closest, off by 0.5°. UKMO ran 2° 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 | — | 28° | — | — | 34° | — | — | 28–34° |
| 14d · 2026-09-06 | 27° | 22° | — | — | 28° | — | — | 22–28° |
| 13d · 2026-09-07 | 28° | 29° | 28° | — | 30° | — | — | 28–30° |
| 12d · 2026-09-08 | 33° | 31° | 26° | — | 26° | — | — | 26–33° |
| 11d · 2026-09-09 | 29° | 31° | 33° | — | 38° | — | — | 29–38° |
| 10d · 2026-09-10 | 32° | 23° | 23° | — | 21° | — | — | 21–32° |
| 9d · 2026-09-11 | 32° | 27° | 30° | — | 31° | — | — | 27–32° |
| 8d · 2026-09-12 | 32° | 31° | 29° | 34° | 28° | — | — | 28–34° |
| 7d · 2026-09-13 | 32° | 31° | 32° | 32° | 32° | — | — | 31–32° |
| 6d · 2026-09-14 | 32° | 30° | 30° | 32° | 32° | 33° | — | 30–33° |
| 5d · 2026-09-15 | 32° | 32° | 32° | 32° | 32° | 31° | 27° | 27–32° |
| 4d · 2026-09-16 | 30° | 30° | 32° | 30° | 33° | 31° | 31° | 30–33° |
| 3d · 2026-09-17 | 30° | 30° | 31° | 32° | 34° | 29° | 31° | 29–34° |
| 2d · 2026-09-18 | 30° | 31° | 32° | 31° | 33° | 30° | 31° | 30–33° |
| 1d · 2026-09-19 | 30° | 32° | 30° | 27° | 34° | 29° | 31° | 27–34° |
| 0d · 2026-09-20 | 30° | 32° | 32° | 31° | 33° | 30° | 29° | 29–33° |
| actual | 32° |
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.