Was the forecast right for Phoenix on Sun Aug 9?
Phoenix, Arizona · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Phoenix's Sun Aug 9 high anywhere from 38° to 43°;by the final call, the day before, the field had settled to a median of 44°. The day verified at 44° against the ECMWF IFS analysis — cloudy.
GFS landed closest, off by 0.1°. AIGFS ran 1° cool.
What every model said, at every lead
Daily-high calls for Sun Aug 9 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 |
|---|---|---|---|---|---|---|---|---|
| 14d · 2026-07-26 | 38° | 43° | 41° | — | 38° | — | — | 38–43° |
| 13d · 2026-07-27 | 35° | 38° | 39° | — | 37° | — | — | 35–39° |
| 12d · 2026-07-28 | 38° | 38° | 34° | — | 41° | — | — | 34–41° |
| 11d · 2026-07-29 | 42° | 42° | 40° | — | 39° | — | — | 39–42° |
| 10d · 2026-07-30 | 38° | 39° | 39° | — | 39° | — | — | 38–39° |
| 9d · 2026-07-31 | 34° | 36° | 40° | 43° | 40° | — | — | 34–43° |
| 8d · 2026-08-01 | 41° | 40° | 42° | 44° | 40° | — | — | 40–44° |
| 7d · 2026-08-02 | 41° | 42° | 40° | 45° | 39° | — | — | 39–45° |
| 6d · 2026-08-03 | 42° | 43° | 39° | 45° | 42° | 43° | 37° | 37–45° |
| 5d · 2026-08-04 | 42° | 43° | 43° | 44° | 42° | 43° | 42° | 42–44° |
| 4d · 2026-08-05 | 42° | 42° | 44° | 44° | 43° | 44° | 42° | 42–44° |
| 3d · 2026-08-06 | 43° | 42° | 43° | 44° | 43° | 44° | 44° | 42–44° |
| 2d · 2026-08-07 | 43° | 42° | 45° | 44° | 43° | 46° | 44° | 42–46° |
| 1d · 2026-08-08 | 43° | 42° | 44° | 43° | 44° | 44° | 44° | 42–44° |
| actual | 44° |
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 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.