Was the forecast right for San Francisco on Fri Jul 31?
San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
5 days out, 7 models put San Francisco's Fri Jul 31 high anywhere from 64° to 79°;by the final call, the day before, the field had settled to a median of 73°. The day verified at 69° against the ECMWF IFS analysis — clear.
ECMWF landed closest, off by 0.3°. ICON ran 6° cool.
What every model said, at every lead
Daily-high calls for Fri Jul 31 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 |
|---|---|---|---|---|---|---|---|---|
| 5d · 2026-07-26 | 73° | 79° | 66° | 64° | 76° | 66° | 73° | 64–79° |
| 4d · 2026-07-27 | 74° | 80° | 69° | 66° | 75° | 69° | 74° | 66–80° |
| 3d · 2026-07-28 | 73° | 75° | 69° | 66° | 70° | 65° | 72° | 65–75° |
| 2d · 2026-07-29 | 73° | 75° | 68° | 67° | 71° | 65° | 74° | 65–75° |
| 1d · 2026-07-30 | 73° | 74° | 69° | 66° | 74° | 63° | 73° | 63–74° |
| 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.