Was the forecast right for Phoenix on Thu Sep 24?
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 Thu Sep 24 high anywhere from 87° to 103°;by the final call, the day before, the field had settled to a median of 95°. The day verified at 88° against the PHX observations — thunderstorms.
AIFS landed closest, off by 0.3°. GEM ran 9° warm.
What every model said, at every lead
Daily-high calls for Thu Sep 24 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 · 2026-09-09 | — | 96° | — | — | 103° | — | — | 96–103° |
| 14d · 2026-09-10 | 87° | 98° | 88° | — | 103° | — | — | 87–103° |
| 13d · 2026-09-11 | 89° | 95° | 98° | — | 91° | — | — | 89–98° |
| 12d · 2026-09-12 | 95° | 96° | 98° | — | 89° | — | — | 89–98° |
| 11d · 2026-09-13 | 92° | 98° | 96° | — | 94° | — | — | 92–98° |
| 10d · 2026-09-14 | 92° | 96° | 87° | — | 103° | — | — | 87–103° |
| 9d · 2026-09-15 | 99° | 100° | 98° | 96° | 100° | — | — | 96–100° |
| 8d · 2026-09-16 | 100° | 88° | 101° | 92° | 100° | — | — | 88–101° |
| 7d · 2026-09-17 | 100° | 93° | 103° | 88° | 96° | — | — | 88–103° |
| 6d · 2026-09-18 | 102° | 94° | 102° | 95° | 98° | 98° | 84° | 84–102° |
| 5d · 2026-09-19 | 103° | 97° | 101° | 99° | 98° | 99° | 94° | 94–103° |
| 4d · 2026-09-20 | 100° | 96° | 100° | 101° | 98° | 86° | 95° | 86–101° |
| 3d · 2026-09-21 | 96° | 94° | 98° | 99° | 97° | 95° | 100° | 94–100° |
| 2d · 2026-09-22 | 97° | 94° | 95° | 99° | 98° | 93° | 97° | 93–99° |
| 1d · 2026-09-23 | 88° | 93° | 91° | 97° | 95° | 97° | 96° | 88–97° |
| actual | 88° |
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. 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.