Was the forecast right for Phoenix on Mon Aug 17?
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 Mon Aug 17 high anywhere from 95° to 108°;by the final call, the day before, the field had settled to a median of 112°. The day verified at 114° against the ECMWF IFS analysis — partly cloudy.
GFS landed closest, off by 0.8°. GEM ran 4° cool.
What every model said, at every lead
Daily-high calls for Mon Aug 17 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 · 2026-08-02 | — | 98° | — | — | 109° | — | — | 98–109° |
| 14d · 2026-08-03 | 106° | 103° | 95° | — | 108° | — | — | 95–108° |
| 13d · 2026-08-04 | 104° | 104° | 106° | — | 106° | — | — | 104–106° |
| 12d · 2026-08-05 | 105° | 103° | 110° | — | 99° | — | — | 99–110° |
| 11d · 2026-08-06 | 101° | 105° | 95° | — | 106° | — | — | 95–106° |
| 10d · 2026-08-07 | 107° | 104° | 100° | — | 107° | — | — | 100–107° |
| 9d · 2026-08-08 | 111° | 102° | 109° | 106° | 107° | — | — | 102–111° |
| 8d · 2026-08-09 | 106° | 106° | 112° | 108° | 105° | — | — | 105–112° |
| 7d · 2026-08-10 | 109° | 108° | 111° | 109° | 107° | — | — | 107–111° |
| 6d · 2026-08-11 | 111° | 106° | 112° | 109° | 105° | 112° | 109° | 105–112° |
| 5d · 2026-08-12 | 112° | 107° | 113° | 108° | 108° | 111° | 109° | 107–113° |
| 4d · 2026-08-13 | 112° | 108° | 112° | 109° | 107° | 111° | 109° | 107–112° |
| 3d · 2026-08-14 | 113° | 109° | 112° | 108° | 108° | 112° | 108° | 108–113° |
| 2d · 2026-08-15 | 112° | 109° | 112° | 108° | 110° | 112° | 109° | 108–112° |
| 1d · 2026-08-16 | 112° | 110° | 112° | 109° | 113° | 112° | 110° | 109–113° |
| actual | 114° |
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.