Was the forecast right for Phoenix on Sun Sep 27?
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 Sun Sep 27 high anywhere from 95° to 110°;by the final call, the day before, the field had settled to a median of 95°. The day verified at 97° against the PHX observations — showers.
ECMWF landed closest, off by 0.9°. UKMO ran 8° cool.
What every model said, at every lead
Daily-high calls for Sun Sep 27 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 · 2026-09-12 | — | 97° | — | — | 97° | — | — | 97–97° |
| 14d · 2026-09-13 | 95° | 105° | 110° | — | 96° | — | — | 95–110° |
| 13d · 2026-09-14 | 104° | 98° | 102° | — | 92° | — | — | 92–104° |
| 12d · 2026-09-15 | 94° | 103° | 106° | — | 101° | — | — | 94–106° |
| 11d · 2026-09-16 | 96° | 98° | 103° | — | 104° | — | — | 96–104° |
| 10d · 2026-09-17 | 102° | 95° | 98° | — | 102° | — | — | 95–102° |
| 9d · 2026-09-18 | 99° | 100° | 101° | 100° | 107° | — | — | 99–107° |
| 8d · 2026-09-19 | 92° | 99° | 94° | 98° | 98° | — | — | 92–99° |
| 7d · 2026-09-20 | 89° | 97° | 97° | 90° | 101° | — | — | 89–101° |
| 6d · 2026-09-21 | 94° | 92° | 96° | 97° | 100° | 97° | 97° | 92–100° |
| 5d · 2026-09-22 | 90° | 92° | 101° | 97° | 96° | 97° | 92° | 90–101° |
| 4d · 2026-09-23 | 93° | 94° | 96° | 95° | 93° | 88° | 93° | 88–96° |
| 3d · 2026-09-24 | 92° | 90° | 98° | 91° | 93° | 94° | 88° | 88–98° |
| 2d · 2026-09-25 | 89° | 90° | 100° | 95° | 93° | 95° | 90° | 89–100° |
| 1d · 2026-09-26 | 92° | 92° | 98° | 95° | 96° | 95° | 90° | 90–98° |
| actual | 97° |
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.