Was the forecast right for Atlanta on Tue Aug 18?
Atlanta, Georgia · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Atlanta's Tue Aug 18 high anywhere from 23° to 34°;by the final call, the day before, the field had settled to a median of 34°. The day verified at 34° against the ECMWF IFS analysis, with 0.5 mm of precipitation — drizzle.
GEM landed closest, off by 0.4°. ECMWF ran 2° warm.
What every model said, at every lead
Daily-high calls for Tue Aug 18 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 · 2026-08-03 | — | 29° | — | — | 37° | — | — | 29–37° |
| 14d · 2026-08-04 | 32° | 34° | 25° | — | 23° | — | — | 23–34° |
| 13d · 2026-08-05 | 34° | 30° | 36° | — | 38° | — | — | 30–38° |
| 12d · 2026-08-06 | 34° | 35° | 28° | — | 36° | — | — | 28–36° |
| 11d · 2026-08-07 | 33° | 36° | 34° | — | 36° | — | — | 33–36° |
| 10d · 2026-08-08 | 32° | 37° | 34° | — | 38° | — | — | 32–38° |
| 9d · 2026-08-09 | 30° | 36° | 38° | 35° | 37° | — | — | 30–38° |
| 8d · 2026-08-10 | 33° | 34° | 35° | 34° | 38° | — | — | 33–38° |
| 7d · 2026-08-11 | 34° | 35° | 36° | 36° | 40° | — | — | 34–40° |
| 6d · 2026-08-12 | 32° | 35° | 36° | 34° | 37° | 38° | 35° | 32–38° |
| 5d · 2026-08-13 | 32° | 35° | 35° | 32° | 39° | 37° | 34° | 32–39° |
| 4d · 2026-08-14 | 33° | 35° | 34° | 32° | 38° | 36° | 36° | 32–38° |
| 3d · 2026-08-15 | 33° | 34° | 35° | 32° | 38° | 34° | 37° | 32–38° |
| 2d · 2026-08-16 | 33° | 34° | 36° | 32° | 37° | 34° | 33° | 32–37° |
| 1d · 2026-08-17 | 33° | 35° | 35° | 33° | 35° | 34° | 33° | 33–35° |
| actual | 34° |
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 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.