Was the forecast right for Phoenix on Wed Aug 5?
Phoenix, Arizona · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
10 days out, 4 models put Phoenix's Wed Aug 5 high anywhere from 39° to 43°;by the final call, the day before, the field had settled to a median of 41°. The day verified at 40° against the ECMWF IFS analysis, with 1.0 mm of precipitation — drizzle.
AIFS landed closest, off by 1.0°. GEM ran 2° warm.
What every model said, at every lead
Daily-high calls for Wed Aug 5 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 |
|---|---|---|---|---|---|---|---|---|
| 10d · 2026-07-26 | 39° | 43° | 39° | — | 41° | — | — | 39–43° |
| 9d · 2026-07-27 | 38° | 37° | 42° | 34° | 41° | — | — | 34–42° |
| 8d · 2026-07-28 | 38° | 40° | 43° | 38° | 42° | — | — | 38–43° |
| 7d · 2026-07-29 | 38° | 40° | 41° | 39° | 41° | — | — | 38–41° |
| 6d · 2026-07-30 | 39° | 41° | 40° | 38° | 40° | 42° | 36° | 36–42° |
| 5d · 2026-07-31 | 39° | 41° | 40° | 40° | 42° | 41° | 44° | 39–44° |
| 4d · 2026-08-01 | 40° | 40° | 40° | 42° | 42° | 42° | 45° | 40–45° |
| 3d · 2026-08-02 | 41° | 41° | 42° | 42° | 42° | 43° | 45° | 41–45° |
| 2d · 2026-08-03 | 41° | 41° | 42° | 42° | 42° | 41° | 43° | 41–43° |
| 1d · 2026-08-04 | 41° | 41° | 41° | 42° | 41° | 41° | 42° | 41–42° |
| actual | 40° |
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.