Was the forecast right for Phoenix on Wed Sep 30?
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 30 high anywhere from 98° to 102°;by the final call, the day before, the field had settled to a median of 82°. The day verified at 86° against the PHX observations — drizzle.
GFS landed closest, off by 0.3°. GEM ran 13° cool.
What every model said, at every lead
Daily-high calls for Wed Sep 30 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 · 2026-09-15 | — | 102° | — | — | 103° | — | — | 102–103° |
| 14d · 2026-09-16 | 100° | 98° | 102° | — | 101° | — | — | 98–102° |
| 13d · 2026-09-17 | 101° | 92° | 99° | — | 106° | — | — | 92–106° |
| 12d · 2026-09-18 | 95° | 98° | 101° | — | 98° | — | — | 95–101° |
| 11d · 2026-09-19 | 100° | 100° | 99° | — | 99° | — | — | 99–100° |
| 10d · 2026-09-20 | 80° | 82° | 99° | — | 89° | — | — | 80–99° |
| 9d · 2026-09-21 | 99° | 93° | 98° | 96° | 104° | — | — | 93–104° |
| 8d · 2026-09-22 | 99° | 95° | 98° | 93° | 89° | — | — | 89–99° |
| 7d · 2026-09-23 | 81° | 74° | 88° | 94° | 84° | — | — | 74–94° |
| 6d · 2026-09-24 | 81° | 82° | 85° | 89° | 91° | 84° | 85° | 81–91° |
| 5d · 2026-09-25 | 84° | 82° | 77° | 91° | 91° | 80° | 91° | 77–91° |
| 4d · 2026-09-26 | 83° | 84° | 83° | 86° | 88° | 89° | 88° | 83–89° |
| 3d · 2026-09-27 | 82° | 84° | 81° | 82° | 88° | 87° | 85° | 81–88° |
| 2d · 2026-09-28 | 82° | 83° | 80° | 72° | 87° | 83° | 87° | 72–87° |
| 1d · 2026-09-29 | 83° | 82° | 79° | 73° | 86° | 79° | 82° | 73–86° |
| actual | 86° |
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.