Was the forecast right for Phoenix on Tue Aug 4?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
9 days out, 5 models put Phoenix's Tue Aug 4 high anywhere from 103° to 109°;by the final call, the day before, the field had settled to a median of 108°. The day verified at 108° against the ECMWF IFS analysis — cloudy.
GEM landed closest, off by 0.1°. UKMO ran 3° warm.
What every model said, at every lead
Daily-high calls for Tue Aug 4 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 · 2026-07-26 | 106° | 109° | 103° | 105° | 107° | — | — | 103–109° |
| 8d · 2026-07-27 | 101° | 104° | 104° | 105° | 104° | — | — | 101–105° |
| 7d · 2026-07-28 | 105° | 106° | 110° | 106° | 111° | — | — | 105–111° |
| 6d · 2026-07-29 | 107° | 108° | 108° | 110° | 110° | 115° | 95° | 95–115° |
| 5d · 2026-07-30 | 108° | 109° | 109° | 109° | 109° | 112° | 108° | 108–112° |
| 4d · 2026-07-31 | 108° | 108° | 108° | 110° | 109° | 109° | 113° | 108–113° |
| 3d · 2026-08-01 | 109° | 107° | 109° | 112° | 111° | 111° | 115° | 107–115° |
| 2d · 2026-08-02 | 109° | 107° | 112° | 111° | 110° | 108° | 113° | 107–113° |
| 1d · 2026-08-03 | 108° | 107° | 108° | 108° | 109° | 108° | 111° | 107–111° |
| actual | 108° |
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.