Was the forecast right for Phoenix on Sun Aug 9?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Phoenix's Sun Aug 9 high anywhere from 100° to 109°;by the final call, the day before, the field had settled to a median of 111°. The day verified at 111° against the ECMWF IFS analysis — cloudy.
GFS landed closest, off by 0.2°. AIGFS ran 3° cool.
What every model said, at every lead
Daily-high calls for Sun Aug 9 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 |
|---|---|---|---|---|---|---|---|---|
| 14d · 2026-07-26 | 100° | 109° | 106° | — | 100° | — | — | 100–109° |
| 13d · 2026-07-27 | 95° | 100° | 102° | — | 98° | — | — | 95–102° |
| 12d · 2026-07-28 | 101° | 100° | 94° | — | 106° | — | — | 94–106° |
| 11d · 2026-07-29 | 107° | 107° | 104° | — | 103° | — | — | 103–107° |
| 10d · 2026-07-30 | 100° | 102° | 103° | — | 102° | — | — | 100–103° |
| 9d · 2026-07-31 | 94° | 96° | 103° | 109° | 103° | — | — | 94–109° |
| 8d · 2026-08-01 | 105° | 105° | 108° | 112° | 104° | — | — | 104–112° |
| 7d · 2026-08-02 | 107° | 108° | 103° | 113° | 102° | — | — | 102–113° |
| 6d · 2026-08-03 | 108° | 110° | 102° | 112° | 108° | 110° | 99° | 99–112° |
| 5d · 2026-08-04 | 108° | 109° | 110° | 112° | 108° | 110° | 107° | 107–112° |
| 4d · 2026-08-05 | 108° | 108° | 111° | 111° | 109° | 112° | 108° | 108–112° |
| 3d · 2026-08-06 | 109° | 107° | 110° | 111° | 110° | 111° | 110° | 107–111° |
| 2d · 2026-08-07 | 110° | 107° | 113° | 110° | 110° | 114° | 111° | 107–114° |
| 1d · 2026-08-08 | 109° | 108° | 111° | 110° | 111° | 111° | 111° | 108–111° |
| actual | 111° |
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 ECMWF IFS analysis (temperature_2m_max). 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.