Was the forecast right for San Francisco on Wed Aug 5?
San Francisco, California · daily high temperature · forecasts from each model's archived runs, verified against ERA5
9 days out, 4 models put San Francisco's Wed Aug 5 high anywhere from 68° to 83°; by the final call the field had settled to a median of 68°. ERA5 says the day verified at 66° — cloudy.
ICON landed closest, off by 0.1°. AIGFS ran 12° hot.
What every model said, at every lead
Daily-high calls for Wed Aug 5 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 · 2026-07-27 | 71° | 79° | 68° | — | 83° | — | — | 68–83° |
| 8d · 2026-07-28 | 72° | 79° | 65° | 70° | 85° | — | — | 65–85° |
| 7d · 2026-07-29 | 70° | 74° | 67° | 72° | 70° | — | — | 67–74° |
| 6d · 2026-07-30 | 71° | 79° | 65° | 71° | 76° | 62° | — | 62–79° |
| 5d · 2026-07-31 | 70° | 77° | 67° | 70° | 78° | 66° | 65° | 65–78° |
| 4d · 2026-08-01 | 69° | 76° | 68° | 70° | 74° | 66° | 67° | 66–76° |
| 3d · 2026-08-02 | 69° | 77° | 68° | 68° | 75° | 65° | 67° | 65–77° |
| 2d · 2026-08-03 | 69° | 76° | 69° | 72° | 76° | 66° | 68° | 66–76° |
| 1d · 2026-08-04 | 70° | 76° | 69° | 70° | 66° | 66° | 68° | 66–76° |
| 0d · 2026-08-05 | 71° | 78° | 68° | 67° | 68° | 66° | 67° | 66–78° |
| 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 ERA5 reanalysis (temperature_2m_max). Archive depth varies by city; receipts exist only for dates the archive watched arrive.