The Spread

Was the forecast right for Phoenix on Wed Aug 5?

Phoenix, Arizona · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

9 days out, 4 models put Phoenix's Wed Aug 5 high anywhere from 39° to 42°; by the final call the field had settled to a median of 41°. The day verified at 40° against the ECMWF IFS analysis, with 1.0 mm of precipitation — drizzle.

ECMWF landed closest, off by 0.2°. GEM ran 2° hot.

9 days out the models said 39–42; it hit 40. ECMWF led (off 0.2°C); GEM ran 2°C hot.
The shareable card for this receipt — what this page looks like pasted into a thread.

What every model said, at every lead

Daily-high calls for Wed Aug 5 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 AIFSAIGFSECMWFGEMGFSICONUKMO Range
9d · 2026-07-27 39° 40° 42° — 41° — — 39–42°
8d · 2026-07-28 38° 40° 42° 42° 43° — — 38–43°
7d · 2026-07-29 37° 40° 40° 41° 41° — — 37–41°
6d · 2026-07-30 41° 40° 40° 39° 42° 39° — 39–42°
5d · 2026-07-31 40° 41° 42° 41° 43° 43° 42° 40–43°
4d · 2026-08-01 40° 40° 40° 40° 43° 40° 42° 40–43°
3d · 2026-08-02 40° 40° 40° 42° 42° 42° 44° 40–44°
2d · 2026-08-03 41° 41° 42° 42° 42° 42° 43° 41–43°
1d · 2026-08-04 41° 41° 41° 43° 42° 40° 42° 40–43°
0d · 2026-08-05 41° 42° 40° 42° 42° 41° 41° 40–42°
actual 40°

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). Archive depth varies by city; receipts exist only for dates the archive watched arrive.