Was the forecast right for Phoenix on Thu Sep 10?
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 Thu Sep 10 high anywhere from 90° to 112°; by the final call the field had settled to a median of 107°. The day verified at 109° against the PHX observations — drizzle.
ECMWF landed closest, off by 1.4°. AIGFS ran 5° cold.
What every model said, at every lead
Daily-high calls for Thu Sep 10 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 · 2026-08-26 | — | 96° | — | — | 102° | — | — | 96–102° |
| 14d · 2026-08-27 | 104° | 87° | — | — | 102° | — | — | 87–104° |
| 13d · 2026-08-28 | 109° | 104° | 90° | — | 112° | — | — | 90–112° |
| 12d · 2026-08-29 | 106° | 105° | 84° | — | 107° | — | — | 84–107° |
| 11d · 2026-08-30 | 100° | 103° | 105° | — | 108° | — | — | 100–108° |
| 10d · 2026-08-31 | 101° | 96° | 102° | — | 96° | — | — | 96–102° |
| 9d · 2026-09-01 | 97° | 94° | 84° | — | 103° | — | — | 84–103° |
| 8d · 2026-09-02 | 86° | 89° | 106° | 88° | 96° | — | — | 86–106° |
| 7d · 2026-09-03 | 102° | 86° | 105° | 79° | 100° | — | — | 79–105° |
| 6d · 2026-09-04 | 105° | 104° | 102° | 87° | 102° | 90° | — | 87–105° |
| 5d · 2026-09-05 | 104° | 106° | 104° | 105° | 108° | 103° | 108° | 103–108° |
| 4d · 2026-09-06 | 104° | 105° | 107° | 104° | 108° | 104° | 95° | 95–108° |
| 3d · 2026-09-07 | 103° | 103° | 108° | 106° | 106° | 108° | 107° | 103–108° |
| 2d · 2026-09-08 | 104° | 102° | 107° | 105° | 106° | 109° | 107° | 102–109° |
| 1d · 2026-09-09 | 106° | 104° | 106° | 106° | 106° | 107° | 108° | 104–108° |
| 0d · 2026-09-10 | 105° | 104° | 108° | 105° | 107° | 107° | 107° | 104–108° |
| actual | 109° |
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.