The Spread

Was the forecast right for San Diego on Mon Aug 31?

San Diego, California · daily high temperature in °C · forecasts from each model's archived runs, verified against the SAN observations

6 days out, 6 models put San Diego's Mon Aug 31 high anywhere from 26° to 30°; by the final call the field had settled to a median of 28°. The day verified at 26° against the SAN observations — cloudy.

GFS landed closest, off by 0.4°. ECMWF ran 5° hot.

6 days out the models said 26–30; it hit 26. GFS led (off 0.4°C); ECMWF ran 5°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 Mon Aug 31 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 San Diego scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
6d · 2026-08-25 30° 28° 29° 26° 27° 27° 26–30°
5d · 2026-08-26 30° 27° 30° 28° 26° 26° 29° 26–30°
4d · 2026-08-27 30° 28° 33° 27° 26° 26° 30° 26–33°
3d · 2026-08-28 29° 28° 31° 27° 26° 27° 30° 26–31°
2d · 2026-08-29 29° 28° 32° 28° 26° 26° 31° 26–32°
1d · 2026-08-30 29° 28° 32° 28° 26° 27° 31° 26–32°
0d · 2026-08-31 28° 28° 31° 27° 26° 27° 30° 26–31°
actual 26°

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 San Diego — 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 SAN observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.