The Spread

Was the forecast right for Phoenix on Tue Sep 8?

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

13 days out, 4 models put Phoenix's Tue Sep 8 high anywhere from 34° to 41°; by the final call the field had settled to a median of 41°. The day verified at 42° against the PHX observations — cloudy.

ICON landed closest, off by 0.2°. AIGFS ran 2° cold.

13 days out the models said 34–41; it hit 42. ICON led (off 0.2°C); AIGFS ran 2°C cold.
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 Tue Sep 8 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
15d · 2026-08-24 — 37° — — 41° — — 37–41°
14d · 2026-08-25 38° 38° — — 34° — — 34–38°
13d · 2026-08-26 39° 38° 41° — 34° — — 34–41°
12d · 2026-08-27 42° 39° 33° — 34° — — 33–42°
11d · 2026-08-28 43° 39° 39° — 42° — — 39–43°
10d · 2026-08-29 42° 39° 44° — 38° — — 38–44°
9d · 2026-08-30 39° 40° 37° — 38° — — 37–40°
8d · 2026-08-31 41° 43° 39° 41° 36° — — 36–43°
7d · 2026-09-01 39° 39° 36° 38° 39° — — 36–39°
6d · 2026-09-02 41° 38° 41° 39° 39° 40° — 38–41°
5d · 2026-09-03 42° 40° 42° 40° 41° 41° 39° 39–42°
4d · 2026-09-04 42° 41° 42° 41° 41° 41° 40° 40–42°
3d · 2026-09-05 42° 40° 43° 41° 41° 42° 40° 40–43°
2d · 2026-09-06 42° 40° 43° 41° 41° 42° 42° 40–43°
1d · 2026-09-07 41° 40° 43° 41° 41° 42° 42° 40–43°
0d · 2026-09-08 41° 41° 43° 41° 41° 42° 42° 41–43°
actual 42°

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