Was the forecast right for Phoenix on Wed Sep 16?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHX observations
13 days out, 4 models put Phoenix's Wed Sep 16 high anywhere from 84° to 106°; by the final call the field had settled to a median of 91°. The day verified at 95° against the PHX observations, with 0.36 in of precipitation — thunderstorms.
GEM landed closest, off by 1.1°. AIGFS ran 6° cold.
What every model said, at every lead
Daily-high calls for Wed Sep 16 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 · 2026-09-01 | — | 98° | — | — | 91° | — | — | 91–98° |
| 14d · 2026-09-02 | 94° | 102° | — | — | 101° | — | — | 94–102° |
| 13d · 2026-09-03 | 106° | 97° | 84° | — | 101° | — | — | 84–106° |
| 12d · 2026-09-04 | 98° | 97° | 92° | — | 92° | — | — | 92–98° |
| 11d · 2026-09-05 | 99° | 101° | 93° | — | 103° | — | — | 93–103° |
| 10d · 2026-09-06 | 88° | 99° | 102° | — | 103° | — | — | 88–103° |
| 9d · 2026-09-07 | 88° | 99° | 92° | — | 97° | — | — | 88–99° |
| 8d · 2026-09-08 | 94° | 98° | 104° | 83° | 99° | — | — | 83–104° |
| 7d · 2026-09-09 | 98° | 99° | 104° | 97° | 97° | — | — | 97–104° |
| 6d · 2026-09-10 | 97° | 99° | 100° | 92° | 100° | 91° | — | 91–100° |
| 5d · 2026-09-11 | 90° | 98° | 94° | 82° | 96° | 97° | 98° | 82–98° |
| 4d · 2026-09-12 | 88° | 96° | 100° | 99° | 99° | 91° | 103° | 88–103° |
| 3d · 2026-09-13 | 90° | 94° | 96° | 96° | 95° | 93° | 103° | 90–103° |
| 2d · 2026-09-14 | 86° | 95° | 90° | 91° | 97° | 93° | 101° | 86–101° |
| 1d · 2026-09-15 | 84° | 86° | 88° | 91° | 94° | 90° | 90° | 84–94° |
| 0d · 2026-09-16 | 91° | 89° | 91° | 94° | 92° | 90° | 90° | 89–94° |
| actual | 95° |
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.