Was the forecast right for Phoenix on Tue Aug 11?
Phoenix, Arizona · daily high temperature in °F · forecasts from each model's archived runs, verified against ERA5
13 days out, 4 models put Phoenix's Tue Aug 11 high anywhere from 96° to 103°; by the final call the field had settled to a median of 104°. ERA5 says the day verified at 103° — cloudy.
AIGFS landed closest, off by 0.5°. GFS ran 2° hot.
What every model said, at every lead
Daily-high calls for Tue Aug 11 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-07-27 | — | 104° | — | — | 102° | — | — | 102–104° |
| 14d · 2026-07-28 | 104° | 102° | — | — | 109° | — | — | 102–109° |
| 13d · 2026-07-29 | 103° | 96° | 101° | — | 101° | — | — | 96–103° |
| 12d · 2026-07-30 | 100° | 100° | 103° | — | 101° | — | — | 100–103° |
| 11d · 2026-07-31 | 101° | 88° | 96° | — | 96° | — | — | 88–101° |
| 10d · 2026-08-01 | 86° | 95° | 99° | — | 104° | — | — | 86–104° |
| 9d · 2026-08-02 | 99° | 104° | 100° | — | 102° | — | — | 99–104° |
| 8d · 2026-08-03 | 101° | 104° | 93° | 98° | 105° | — | — | 93–105° |
| 7d · 2026-08-04 | 103° | 104° | 107° | 106° | 105° | — | — | 103–107° |
| 6d · 2026-08-05 | 104° | 105° | 106° | 104° | 103° | 92° | — | 92–106° |
| 5d · 2026-08-06 | 103° | 105° | 106° | 103° | 104° | 95° | 100° | 95–106° |
| 4d · 2026-08-07 | 102° | 103° | 102° | 102° | 104° | 95° | 101° | 95–104° |
| 3d · 2026-08-08 | 101° | 100° | 102° | 96° | 103° | 92° | 102° | 92–103° |
| 2d · 2026-08-09 | 102° | 102° | 104° | 105° | 105° | 102° | 103° | 102–105° |
| 1d · 2026-08-10 | 103° | 102° | 104° | 101° | 106° | 103° | 104° | 101–106° |
| 0d · 2026-08-11 | 102° | 102° | 104° | 104° | 105° | 104° | 105° | 102–105° |
| actual | 103° |
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.