Was the forecast right for Phoenix on Sun Aug 16?
Phoenix, Arizona · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put Phoenix's Sun Aug 16 high anywhere from 34° to 40°;by the final call, the day before, the field had settled to a median of 42°. The day verified at 43° against the ECMWF IFS analysis, with 0.3 mm of precipitation — drizzle.
GFS landed closest, off by 0.2°. UKMO ran 4° cool.
What every model said, at every lead
Daily-high calls for Sun Aug 16 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 · 2026-08-01 | — | 40° | — | — | 40° | — | — | 40–40° |
| 14d · 2026-08-02 | 34° | 36° | 39° | — | 40° | — | — | 34–40° |
| 13d · 2026-08-03 | 40° | 39° | 33° | — | 42° | — | — | 33–42° |
| 12d · 2026-08-04 | 39° | 41° | 37° | — | 41° | — | — | 37–41° |
| 11d · 2026-08-05 | 39° | 39° | 43° | — | 40° | — | — | 39–43° |
| 10d · 2026-08-06 | 36° | 40° | 33° | — | 41° | — | — | 33–41° |
| 9d · 2026-08-07 | 39° | 40° | 42° | 42° | 41° | — | — | 39–42° |
| 8d · 2026-08-08 | 43° | 40° | 43° | 41° | 41° | — | — | 40–43° |
| 7d · 2026-08-09 | 43° | 40° | 43° | 42° | 40° | — | — | 40–43° |
| 6d · 2026-08-10 | 41° | 41° | 42° | 41° | 41° | 42° | 42° | 41–42° |
| 5d · 2026-08-11 | 42° | 39° | 42° | 41° | 40° | 41° | 41° | 39–42° |
| 4d · 2026-08-12 | 42° | 41° | 42° | 40° | 42° | 42° | 41° | 40–42° |
| 3d · 2026-08-13 | 42° | 41° | 43° | 40° | 42° | 43° | 40° | 40–43° |
| 2d · 2026-08-14 | 43° | 41° | 43° | 40° | 41° | 42° | 41° | 40–43° |
| 1d · 2026-08-15 | 42° | 41° | 42° | 41° | 43° | 42° | 39° | 39–43° |
| actual | 43° |
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.