The Spread

Was the forecast right for San Francisco on Thu Aug 27?

San Francisco, California · daily high temperature in °C · forecasts from each model's archived runs, verified against the SFOC1 observations

5 days out, 7 models put San Francisco's Thu Aug 27 high anywhere from 20° to 26°; by the final call the field had settled to a median of 23°. The day verified at 21° against the SFOC1 observations — cloudy.

ECMWF landed closest, off by 0.2°. AIGFS ran 4° hot.

5 days out the models said 20–26; it hit 21. ECMWF led (off 0.2°C); AIGFS ran 4°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 Thu Aug 27 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 Francisco scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
5d · 2026-08-22 22° 26° 21° 20° 22° 20° 21° 20–26°
4d · 2026-08-23 22° 26° 20° 21° 20° 20° 23° 20–26°
3d · 2026-08-24 23° 25° 22° 21° 22° 21° 27° 21–27°
2d · 2026-08-25 24° 26° 23° 22° 23° 20° 21° 20–26°
1d · 2026-08-26 23° 26° 22° 19° 22° 20° 23° 19–26°
0d · 2026-08-27 23° 25° 21° 20° 23° 20° 23° 20–25°
actual 21°

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 Francisco — 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 SFOC1 observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.