The Spread

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

San Diego, California · daily high temperature in °F · 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 79° to 86°; by the final call the field had settled to a median of 83°. The day verified at 78° against the SAN observations — cloudy.

GFS landed closest, off by 0.7°. ECMWF ran 10° hot.

6 days out the models said 79–86; it hit 78. GFS led (off 0.7°F); ECMWF ran 10°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 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 86° 82° 85° 79° 81° 81° 79–86°
5d · 2026-08-26 86° 81° 87° 82° 78° 79° 83° 78–87°
4d · 2026-08-27 85° 82° 91° 81° 79° 79° 86° 79–91°
3d · 2026-08-28 84° 82° 88° 80° 79° 80° 86° 79–88°
2d · 2026-08-29 85° 83° 89° 82° 79° 79° 87° 79–89°
1d · 2026-08-30 84° 83° 89° 82° 79° 80° 88° 79–89°
0d · 2026-08-31 83° 83° 88° 81° 79° 80° 86° 79–88°
actual 78°

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.