Was the forecast right for San Diego on Sun Sep 20?
San Diego, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the SAN observations
13 days out, 4 models put San Diego's Sun Sep 20 high anywhere from 80° to 86°; by the final call the field had settled to a median of 76°. The day verified at 77° against the SAN observations — cloudy.
GEM landed closest, off by 0.2°. ECMWF ran 5° warm.
What every model said, at every lead
Daily-high calls for Sun Sep 20 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 Diego scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-09-05 | — | 96° | — | — | 81° | — | — | 81–96° |
| 14d · 2026-09-06 | 80° | 81° | — | — | 82° | — | — | 80–82° |
| 13d · 2026-09-07 | 82° | 86° | 85° | — | 80° | — | — | 80–86° |
| 12d · 2026-09-08 | 77° | 78° | 91° | — | 78° | — | — | 77–91° |
| 11d · 2026-09-09 | 76° | 76° | 76° | — | 80° | — | — | 76–80° |
| 10d · 2026-09-10 | 81° | 88° | 77° | — | 73° | — | — | 73–88° |
| 9d · 2026-09-11 | 78° | 78° | 82° | — | 82° | — | — | 78–82° |
| 8d · 2026-09-12 | 77° | 78° | 90° | 79° | 79° | — | — | 77–90° |
| 7d · 2026-09-13 | 77° | 76° | 80° | 79° | 74° | — | — | 74–80° |
| 6d · 2026-09-14 | 77° | 77° | 81° | 76° | 75° | 79° | — | 75–81° |
| 5d · 2026-09-15 | 76° | 75° | 83° | 78° | 74° | 76° | 77° | 74–83° |
| 4d · 2026-09-16 | 76° | 75° | 83° | 77° | 75° | 75° | 75° | 75–83° |
| 3d · 2026-09-17 | 75° | 75° | 81° | 76° | 76° | 77° | 76° | 75–81° |
| 2d · 2026-09-18 | 75° | 76° | 82° | 76° | 76° | 77° | 76° | 75–82° |
| 1d · 2026-09-19 | 75° | 75° | 82° | 76° | 75° | 76° | 78° | 75–82° |
| 0d · 2026-09-20 | 75° | 75° | 82° | 77° | 74° | 76° | 76° | 74–82° |
| actual | 77° |
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 Diego — 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 SAN observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.