Was the forecast right for San Francisco on Thu Sep 10?
San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the SFOC1 observations
14 days out, 4 models put San Francisco's Thu Sep 10 high anywhere from 63° to 85°;by the final call, the day before, the field had settled to a median of 74°. The day verified at 76° against the SFOC1 observations — cloudy.
UKMO landed closest, off by 1.9°. AIGFS ran 7° warm.
What every model said, at every lead
Daily-high calls for Thu Sep 10 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, labeled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-08-26 | — | 64° | — | — | 63° | — | — | 63–64° |
| 14d · 2026-08-27 | 78° | 85° | 63° | — | 74° | — | — | 63–85° |
| 13d · 2026-08-28 | 78° | 86° | 64° | — | 70° | — | — | 64–86° |
| 12d · 2026-08-29 | 80° | 84° | 69° | — | 72° | — | — | 69–84° |
| 11d · 2026-08-30 | 68° | 68° | 69° | — | 79° | — | — | 68–79° |
| 10d · 2026-08-31 | 68° | 72° | 63° | — | 76° | — | — | 63–76° |
| 9d · 2026-09-01 | 66° | 71° | 66° | 70° | 72° | — | — | 66–72° |
| 8d · 2026-09-02 | 67° | 69° | 71° | 68° | 65° | — | — | 65–71° |
| 7d · 2026-09-03 | 83° | 88° | 74° | 64° | 66° | — | — | 64–88° |
| 6d · 2026-09-04 | 84° | 81° | 78° | 64° | 86° | 62° | — | 62–86° |
| 5d · 2026-09-05 | 86° | 91° | 76° | 84° | 82° | 81° | 78° | 76–91° |
| 4d · 2026-09-06 | 84° | 87° | 72° | 72° | 82° | 75° | 79° | 72–87° |
| 3d · 2026-09-07 | 82° | 86° | 72° | 72° | 77° | 74° | 76° | 72–86° |
| 2d · 2026-09-08 | 78° | 83° | 72° | 71° | 77° | 70° | 75° | 70–83° |
| 1d · 2026-09-09 | 80° | 83° | 74° | 71° | 79° | 71° | 74° | 71–83° |
| actual | 76° |
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. The actual values are the ones in hand when this day was verified, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; verified days exist only for dates the archive watched arrive.