Was the forecast right for Phoenix on Fri Aug 28?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against the PHX observations
9 days out, 5 models put Phoenix's Fri Aug 28 high anywhere from 107° to 115°;by the final call, the day before, the field had settled to a median of 109°. The day verified at 112° against the PHX observations — drizzle.
ICON landed closest, off by 0.2°. GEM ran 7° cool.
What every model said, at every lead
Daily-high calls for Fri Aug 28 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 |
|---|---|---|---|---|---|---|---|---|
| 9d · 2026-08-19 | 112° | 107° | 115° | 109° | 108° | — | — | 107–115° |
| 8d · 2026-08-20 | 111° | 106° | 114° | 111° | 114° | — | — | 106–114° |
| 7d · 2026-08-21 | 112° | 108° | 115° | 111° | 113° | — | — | 108–115° |
| 6d · 2026-08-22 | 110° | 108° | 116° | 112° | 114° | 113° | 114° | 108–116° |
| 5d · 2026-08-23 | 108° | 109° | 113° | 111° | 113° | 109° | 112° | 108–113° |
| 4d · 2026-08-24 | 108° | 108° | 113° | 107° | 109° | 112° | 111° | 107–113° |
| 3d · 2026-08-25 | 109° | 108° | 114° | 109° | 110° | 112° | 111° | 108–114° |
| 2d · 2026-08-26 | 109° | 109° | 113° | 112° | 111° | 113° | 111° | 109–113° |
| 1d · 2026-08-27 | 109° | 109° | 109° | 105° | 110° | 112° | 109° | 105–112° |
| actual | 112° |
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.