Was the forecast right for Phoenix on Thu Aug 6?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against ERA5
10 days out, 4 models put Phoenix's Thu Aug 6 high anywhere from 101° to 108°; by the final call the field had settled to a median of 107°. ERA5 says the day verified at 104° with 0.01 in of precipitation — drizzle.
ECMWF landed closest, off by 0.7°. GEM ran 6° hot.
What every model said, at every lead
Daily-high calls for Thu Aug 6 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 |
|---|---|---|---|---|---|---|---|---|
| 10d · 2026-07-27 | 101° | 106° | 107° | — | 108° | — | — | 101–108° |
| 9d · 2026-07-28 | 100° | 103° | 107° | — | 107° | — | — | 100–107° |
| 8d · 2026-07-29 | 102° | 106° | 100° | 104° | 104° | — | — | 100–106° |
| 7d · 2026-07-30 | 105° | 105° | 107° | 103° | 108° | — | — | 103–108° |
| 6d · 2026-07-31 | 104° | 106° | 105° | 102° | 111° | 104° | — | 102–111° |
| 5d · 2026-08-01 | 102° | 104° | 106° | 104° | 108° | 109° | 103° | 102–109° |
| 4d · 2026-08-02 | 103° | 104° | 105° | 108° | 107° | 110° | 109° | 103–110° |
| 3d · 2026-08-03 | 106° | 106° | 107° | 108° | 110° | 112° | 110° | 106–112° |
| 2d · 2026-08-04 | 106° | 106° | 108° | 112° | 109° | 109° | 109° | 106–112° |
| 1d · 2026-08-05 | 104° | 105° | 106° | 110° | 107° | 106° | 108° | 104–110° |
| 0d · 2026-08-06 | 103° | 106° | 103° | 110° | 108° | 107° | 107° | 103–110° |
| actual | 104° |
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 ERA5 reanalysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.