Was the forecast right for Phoenix on Tue Sep 29?
Phoenix, Arizona · daily high temperature in °C · 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 36° to 44°;by the final call, the day before, the field had settled to a median of 26°. The day verified at 28° against the PHX observations, with 11.4 mm of precipitation — showers.
UKMO landed closest, off by 0.3°. GEM ran 5° 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 | — | 33° | — | — | 34° | — | — | 33–34° |
| 14d · 2026-09-15 | 36° | 40° | 44° | — | 39° | — | — | 36–44° |
| 13d · 2026-09-16 | 36° | 37° | 40° | — | 38° | — | — | 36–40° |
| 12d · 2026-09-17 | 39° | 35° | 39° | — | 40° | — | — | 35–40° |
| 11d · 2026-09-18 | 34° | 38° | 41° | — | 41° | — | — | 34–41° |
| 10d · 2026-09-19 | 38° | 37° | 39° | — | 37° | — | — | 37–39° |
| 9d · 2026-09-20 | 29° | 28° | 40° | 37° | 36° | — | — | 28–40° |
| 8d · 2026-09-21 | 33° | 32° | 37° | 37° | 39° | — | — | 32–39° |
| 7d · 2026-09-22 | 35° | 32° | 36° | 33° | 29° | — | — | 29–36° |
| 6d · 2026-09-23 | 23° | 24° | 28° | 34° | 30° | 27° | 27° | 23–34° |
| 5d · 2026-09-24 | 23° | 24° | 26° | 30° | 32° | 26° | 26° | 23–32° |
| 4d · 2026-09-25 | 25° | 25° | 27° | 31° | 32° | 27° | 27° | 25–32° |
| 3d · 2026-09-26 | 23° | 28° | 26° | 30° | 31° | 30° | 28° | 23–31° |
| 2d · 2026-09-27 | 23° | 27° | 26° | 24° | 30° | 29° | 27° | 23–30° |
| 1d · 2026-09-28 | 24° | 27° | 26° | 23° | 29° | 26° | 28° | 23–29° |
| actual | 28° |
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.