Was the forecast right for San Francisco on Mon Aug 31?
San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the SFOC1 observations
9 days out, 4 models put San Francisco's Mon Aug 31 high anywhere from 66° to 75°; by the final call the field had settled to a median of 63°. The day verified at 65° against the SFOC1 observations — cloudy.
GFS landed closest, off by 0.0°. GEM ran 3° cold.
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 Francisco scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 9d · 2026-08-22 | 66° | 75° | 68° | — | 70° | — | — | 66–75° |
| 8d · 2026-08-23 | 63° | 63° | 65° | 63° | 64° | — | — | 63–65° |
| 7d · 2026-08-24 | 66° | 65° | 61° | 62° | 66° | — | — | 61–66° |
| 6d · 2026-08-25 | 65° | 65° | 61° | 60° | 65° | 64° | — | 60–65° |
| 5d · 2026-08-26 | 64° | 64° | 63° | 61° | 65° | 63° | 63° | 61–65° |
| 4d · 2026-08-27 | 63° | 65° | 62° | 60° | 66° | 63° | 65° | 60–66° |
| 3d · 2026-08-28 | 64° | 64° | 62° | 61° | 67° | 63° | 64° | 61–67° |
| 2d · 2026-08-29 | 63° | 64° | 62° | 63° | 67° | 63° | 62° | 62–67° |
| 1d · 2026-08-30 | 63° | 64° | 63° | 62° | 66° | 62° | 64° | 62–66° |
| 0d · 2026-08-31 | 63° | 65° | 63° | 62° | 65° | 63° | 64° | 62–65° |
| actual | 65° |
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.