Was the forecast right for Phoenix on Wed Sep 23?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHX observations
14 days out, 4 models put Phoenix's Wed Sep 23 high anywhere from 93° to 102°;by the final call, the day before, the field had settled to a median of 96°. The day verified at 99° against the PHX observations — cloudy.
ECMWF landed closest, off by 1.0°. AIFS ran 7° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 23 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 · 2026-09-08 | — | 99° | — | — | 100° | — | — | 99–100° |
| 14d · 2026-09-09 | 93° | 100° | 97° | — | 102° | — | — | 93–102° |
| 13d · 2026-09-10 | 90° | 99° | 90° | — | 99° | — | — | 90–99° |
| 12d · 2026-09-11 | 96° | 99° | 92° | — | 104° | — | — | 92–104° |
| 11d · 2026-09-12 | 92° | 94° | 101° | — | 100° | — | — | 92–101° |
| 10d · 2026-09-13 | 94° | 102° | 99° | — | 99° | — | — | 94–102° |
| 9d · 2026-09-14 | 96° | 96° | 90° | 94° | 99° | — | — | 90–99° |
| 8d · 2026-09-15 | 100° | 100° | 99° | 104° | 101° | — | — | 99–104° |
| 7d · 2026-09-16 | 99° | 97° | 99° | 101° | 98° | — | — | 97–101° |
| 6d · 2026-09-17 | 99° | 98° | 100° | 98° | 99° | 98° | 99° | 98–100° |
| 5d · 2026-09-18 | 100° | 95° | 102° | 100° | 97° | 99° | 102° | 95–102° |
| 4d · 2026-09-19 | 100° | 96° | 102° | 100° | 94° | 99° | 101° | 94–102° |
| 3d · 2026-09-20 | 99° | 95° | 100° | 98° | 97° | 96° | 100° | 95–100° |
| 2d · 2026-09-21 | 92° | 93° | 98° | 98° | 92° | 94° | 96° | 92–98° |
| 1d · 2026-09-22 | 92° | 93° | 98° | 98° | 93° | 96° | 98° | 92–98° |
| actual | 99° |
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 PHX observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.