Was the forecast right for Phoenix on Tue Sep 29?
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 Tue Sep 29 high anywhere from 97° to 110°;by the final call, the day before, the field had settled to a median of 79°. The day verified at 83° against the PHX observations, with 0.45 in of precipitation — showers.
UKMO landed closest, off by 0.5°. GEM ran 10° cool.
What every model said, at every lead
Daily-high calls for Tue Sep 29 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 · 2026-09-14 | — | 91° | — | — | 94° | — | — | 91–94° |
| 14d · 2026-09-15 | 97° | 104° | 110° | — | 102° | — | — | 97–110° |
| 13d · 2026-09-16 | 96° | 99° | 104° | — | 100° | — | — | 96–104° |
| 12d · 2026-09-17 | 102° | 96° | 103° | — | 104° | — | — | 96–104° |
| 11d · 2026-09-18 | 92° | 100° | 106° | — | 106° | — | — | 92–106° |
| 10d · 2026-09-19 | 100° | 99° | 102° | — | 98° | — | — | 98–102° |
| 9d · 2026-09-20 | 84° | 82° | 104° | 98° | 96° | — | — | 82–104° |
| 8d · 2026-09-21 | 92° | 89° | 99° | 99° | 102° | — | — | 89–102° |
| 7d · 2026-09-22 | 94° | 90° | 96° | 91° | 84° | — | — | 84–96° |
| 6d · 2026-09-23 | 74° | 76° | 83° | 93° | 85° | 81° | 81° | 74–93° |
| 5d · 2026-09-24 | 74° | 76° | 79° | 85° | 90° | 79° | 78° | 74–90° |
| 4d · 2026-09-25 | 77° | 77° | 81° | 88° | 90° | 80° | 80° | 77–90° |
| 3d · 2026-09-26 | 74° | 82° | 78° | 86° | 87° | 86° | 83° | 74–87° |
| 2d · 2026-09-27 | 73° | 81° | 79° | 76° | 86° | 84° | 81° | 73–86° |
| 1d · 2026-09-28 | 74° | 81° | 78° | 73° | 84° | 79° | 82° | 73–84° |
| actual | 83° |
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.