Was the forecast right for Phoenix on Thu Aug 13?
Phoenix, Arizona · daily high temperature in °C · forecasts from each model's archived runs, verified against ERA5
13 days out, 4 models put Phoenix's Thu Aug 13 high anywhere from 38° to 41°; by the final call the field had settled to a median of 37°. ERA5 says the day verified at 36° with 0.8 mm of precipitation — drizzle.
AIGFS landed closest, off by 0.6°. ICON ran 2° cold.
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 Phoenix scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-07-29 | — | 40° | — | — | 40° | — | — | 40–40° |
| 14d · 2026-07-30 | 32° | 40° | — | — | 41° | — | — | 32–41° |
| 13d · 2026-07-31 | 41° | 38° | 40° | — | 41° | — | — | 38–41° |
| 12d · 2026-08-01 | 36° | 32° | 40° | — | 42° | — | — | 32–42° |
| 11d · 2026-08-02 | 37° | 37° | 40° | — | 40° | — | — | 37–40° |
| 10d · 2026-08-03 | 36° | 41° | 36° | — | 42° | — | — | 36–42° |
| 9d · 2026-08-04 | 34° | 36° | 40° | — | 41° | — | — | 34–41° |
| 8d · 2026-08-05 | 34° | 36° | 32° | 42° | 40° | — | — | 32–42° |
| 7d · 2026-08-06 | 35° | 35° | 41° | 39° | 37° | — | — | 35–41° |
| 6d · 2026-08-07 | 34° | 38° | 39° | 39° | 39° | 35° | — | 34–39° |
| 5d · 2026-08-08 | 37° | 38° | 35° | 38° | 38° | 33° | 37° | 33–38° |
| 4d · 2026-08-09 | 38° | 38° | 36° | 36° | 35° | 33° | 32° | 32–38° |
| 3d · 2026-08-10 | 35° | 38° | 36° | 36° | 36° | 34° | 39° | 34–39° |
| 2d · 2026-08-11 | 36° | 37° | 35° | 37° | 39° | 33° | 37° | 33–39° |
| 1d · 2026-08-12 | 36° | 37° | 35° | 37° | 39° | 33° | 38° | 33–39° |
| 0d · 2026-08-13 | 34° | 37° | 37° | 37° | 37° | 34° | 38° | 34–38° |
| actual | 36° |
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 Phoenix — 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 ERA5 reanalysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.