The Spread

Was the forecast right for Phoenix on Wed Aug 12?

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 Wed Aug 12 high anywhere from 96° to 107°; by the final call the field had settled to a median of 100°. ERA5 says the day verified at 95° with 0.59 in of precipitation — rain.

AIFS landed closest, off by 0.9°. ECMWF ran 9° hot.

13 days out the models said 96–107; it hit 95. AIFS led (off 0.9°F); ECMWF ran 9°F 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 12 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 · 2026-07-28 102° 104° 102–104°
14d · 2026-07-29 92° 100° 104° 92–104°
13d · 2026-07-30 96° 101° 100° 107° 96–107°
12d · 2026-07-31 105° 98° 101° 100° 98–105°
11d · 2026-08-01 91° 98° 93° 105° 91–105°
10d · 2026-08-02 102° 104° 101° 101° 101–104°
9d · 2026-08-03 101° 106° 93° 104° 93–106°
8d · 2026-08-04 98° 101° 103° 105° 106° 98–106°
7d · 2026-08-05 98° 102° 98° 107° 104° 98–107°
6d · 2026-08-06 94° 101° 105° 105° 104° 94° 94–105°
5d · 2026-08-07 92° 96° 101° 105° 103° 94° 99° 92–105°
4d · 2026-08-08 93° 98° 102° 90° 101° 89° 93° 89–102°
3d · 2026-08-09 96° 95° 104° 90° 96° 93° 100° 90–104°
2d · 2026-08-10 93° 96° 102° 94° 102° 93° 93° 93–102°
1d · 2026-08-11 94° 91° 104° 91° 102° 89° 93° 89–104°
0d · 2026-08-12 94° 100° 104° 101° 102° 100° 100° 94–104°
actual 95°

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.