Was the forecast right for San Francisco on Mon Aug 3?
San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
8 days out, 5 models put San Francisco's Mon Aug 3 high anywhere from 64° to 77°;by the final call, the day before, the field had settled to a median of 75°. The day verified at 69° against the ECMWF IFS analysis — partly cloudy.
ICON landed closest, off by 2.4°. GFS ran 15° warm.
What every model said, at every lead
Daily-high calls for Mon Aug 3 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 |
|---|---|---|---|---|---|---|---|---|
| 8d · 2026-07-26 | 73° | 77° | 64° | 64° | 77° | — | — | 64–77° |
| 7d · 2026-07-27 | 74° | 75° | 64° | 69° | 78° | — | — | 64–78° |
| 6d · 2026-07-28 | 74° | 74° | 64° | 65° | 80° | 64° | 70° | 64–80° |
| 5d · 2026-07-29 | 75° | 77° | 72° | 70° | 81° | 65° | 78° | 65–81° |
| 4d · 2026-07-30 | 76° | 81° | 72° | 71° | 78° | 66° | 73° | 66–81° |
| 3d · 2026-07-31 | 76° | 84° | 72° | 74° | 83° | 66° | 76° | 66–84° |
| 2d · 2026-08-01 | 76° | 83° | 72° | 75° | 79° | 67° | 76° | 67–83° |
| 1d · 2026-08-02 | 74° | 84° | 74° | 76° | 84° | 67° | 75° | 67–84° |
| actual | 69° |
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.