Was the forecast right for San Francisco on Sun Aug 9?
San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
14 days out, 4 models put San Francisco's Sun Aug 9 high anywhere from 63° to 74°;by the final call, the day before, the field had settled to a median of 74°. The day verified at 66° against the ECMWF IFS analysis — partly cloudy.
ICON landed closest, off by 1.9°. AIGFS ran 18° warm.
What every model said, at every lead
Daily-high calls for Sun Aug 9 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 |
|---|---|---|---|---|---|---|---|---|
| 14d · 2026-07-26 | 66° | 74° | 63° | — | 74° | — | — | 63–74° |
| 13d · 2026-07-27 | 67° | 70° | 65° | — | 68° | — | — | 65–70° |
| 12d · 2026-07-28 | 67° | 72° | 64° | — | 77° | — | — | 64–77° |
| 11d · 2026-07-29 | 73° | 75° | 62° | — | 71° | — | — | 62–75° |
| 10d · 2026-07-30 | 68° | 71° | 65° | — | 74° | — | — | 65–74° |
| 9d · 2026-07-31 | 66° | 74° | 65° | 62° | 72° | — | — | 62–74° |
| 8d · 2026-08-01 | 70° | 72° | 65° | 72° | 72° | — | — | 65–72° |
| 7d · 2026-08-02 | 71° | 74° | 65° | 70° | 73° | — | — | 65–74° |
| 6d · 2026-08-03 | 71° | 75° | 65° | 71° | 73° | 63° | 67° | 63–75° |
| 5d · 2026-08-04 | 73° | 81° | 68° | 71° | 72° | 62° | 67° | 62–81° |
| 4d · 2026-08-05 | 73° | 80° | 68° | 67° | 73° | 64° | 69° | 64–80° |
| 3d · 2026-08-06 | 75° | 81° | 74° | 71° | 74° | 63° | 69° | 63–81° |
| 2d · 2026-08-07 | 75° | 80° | 74° | 74° | 76° | 63° | 70° | 63–80° |
| 1d · 2026-08-08 | 74° | 84° | 74° | 74° | 79° | 64° | 76° | 64–84° |
| 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 ECMWF IFS analysis (temperature_2m_max). The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.