Was the forecast right for Phoenix on Sun Aug 23?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHX observations
3 days out, 7 models put Phoenix's Sun Aug 23 high anywhere from 102° to 112°; by the final call the field had settled to a median of 110°. The day verified at 113° against the PHX observations — drizzle.
ICON landed closest, off by 0.2°. AIFS ran 5° cold.
What every model said, at every lead
Daily-high calls for Sun Aug 23 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 |
|---|---|---|---|---|---|---|---|---|
| 3d · 2026-08-20 | 105° | 107° | 111° | 102° | 111° | 112° | 107° | 102–112° |
| 2d · 2026-08-21 | 107° | 108° | 112° | 104° | 111° | 113° | 105° | 104–113° |
| 1d · 2026-08-22 | 107° | 107° | 113° | 106° | 111° | 114° | 110° | 106–114° |
| 0d · 2026-08-23 | 108° | 110° | 114° | 108° | 112° | 113° | 110° | 108–114° |
| actual | 113° |
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.