Was the forecast right for Phoenix on Wed Sep 9?
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 9 high anywhere from 96° to 102°;by the final call, the day before, the field had settled to a median of 106°. The day verified at 107° against the PHX observations — cloudy.
UKMO landed closest, off by 0.6°. AIGFS ran 5° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 9 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, labeled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-25 | — | 102° | — | — | 102° | — | — | 102–102° |
| 14d · 2026-08-26 | 98° | 102° | 102° | — | 96° | — | — | 96–102° |
| 13d · 2026-08-27 | 103° | 101° | 97° | — | 94° | — | — | 94–103° |
| 12d · 2026-08-28 | 107° | 100° | 105° | — | 97° | — | — | 97–107° |
| 11d · 2026-08-29 | 103° | 104° | 96° | — | 108° | — | — | 96–108° |
| 10d · 2026-08-30 | 105° | 104° | 106° | — | 105° | — | — | 104–106° |
| 9d · 2026-08-31 | 93° | 93° | 85° | 102° | 107° | — | — | 85–107° |
| 8d · 2026-09-01 | 92° | 92° | 98° | 90° | 104° | — | — | 90–104° |
| 7d · 2026-09-02 | 96° | 97° | 105° | 85° | 102° | — | — | 85–105° |
| 6d · 2026-09-03 | 104° | 96° | 106° | 86° | 103° | 110° | — | 86–110° |
| 5d · 2026-09-04 | 106° | 102° | 105° | 104° | 104° | 102° | 107° | 102–107° |
| 4d · 2026-09-05 | 106° | 104° | 104° | 104° | 106° | 105° | 104° | 104–106° |
| 3d · 2026-09-06 | 106° | 102° | 107° | 106° | 106° | 106° | 108° | 102–108° |
| 2d · 2026-09-07 | 107° | 101° | 106° | 104° | 105° | 106° | 107° | 101–107° |
| 1d · 2026-09-08 | 106° | 102° | 106° | 106° | 104° | 106° | 106° | 102–106° |
| actual | 107° |
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 day was verified, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; verified days exist only for dates the archive watched arrive.