Was the forecast right for San Francisco on Fri Sep 11?
San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the SFOC1 observations
13 days out, 4 models put San Francisco's Fri Sep 11 high anywhere from 66° to 88°; by the final call the field had settled to a median of 67°. The day verified at 66° against the SFOC1 observations — cloudy.
ECMWF landed closest, off by 0.5°. AIGFS ran 7° hot.
What every model said, at every lead
Daily-high calls for Fri Sep 11 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 |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-27 | — | 66° | — | — | 69° | — | — | 66–69° |
| 14d · 2026-08-28 | 75° | 72° | — | — | 70° | — | — | 70–75° |
| 13d · 2026-08-29 | 73° | 80° | 66° | — | 88° | — | — | 66–88° |
| 12d · 2026-08-30 | 75° | 90° | 66° | — | 69° | — | — | 66–90° |
| 11d · 2026-08-31 | 69° | 70° | 73° | — | 88° | — | — | 69–88° |
| 10d · 2026-09-01 | 66° | 68° | 63° | — | 71° | — | — | 63–71° |
| 9d · 2026-09-02 | 65° | 71° | 74° | — | 69° | — | — | 65–74° |
| 8d · 2026-09-03 | 77° | 65° | 68° | 63° | 68° | — | — | 63–77° |
| 7d · 2026-09-04 | 72° | 74° | 69° | 66° | 71° | — | — | 66–74° |
| 6d · 2026-09-05 | 73° | 81° | 67° | 72° | 73° | 68° | — | 67–81° |
| 5d · 2026-09-06 | 73° | 77° | 66° | 72° | 70° | 69° | 76° | 66–77° |
| 4d · 2026-09-07 | 70° | 77° | 66° | 65° | 69° | 64° | 68° | 64–77° |
| 3d · 2026-09-08 | 70° | 76° | 67° | 66° | 68° | 63° | 68° | 63–76° |
| 2d · 2026-09-09 | 70° | 74° | 67° | 67° | 69° | 63° | 69° | 63–74° |
| 1d · 2026-09-10 | 71° | 71° | 67° | 69° | 69° | 63° | 66° | 63–71° |
| 0d · 2026-09-11 | 69° | 73° | 66° | 67° | 70° | 63° | 65° | 63–73° |
| actual | 66° |
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.