The Spread

Was the forecast right for San Francisco on Mon Sep 14?

San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against the SFOC1 observations

13 days out, 4 models put San Francisco's Mon Sep 14 high anywhere from 65° to 70°; by the final call the field had settled to a median of 73°. The day verified at 71° against the SFOC1 observations — cloudy.

GFS landed closest, off by 1.8°. AIGFS ran 4° hot.

13 days out the models said 65–70; it hit 71. GFS led (off 1.8°F); AIGFS ran 4°F hot.
The shareable card for this receipt — what this page looks like pasted into a thread.

What every model said, at every lead

Daily-high calls for Mon Sep 14 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 AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-30 71° 78° 71–78°
14d · 2026-08-31 63° 88° 68° 63–88°
13d · 2026-09-01 68° 70° 67° 65° 65–70°
12d · 2026-09-02 65° 73° 64° 70° 64–73°
11d · 2026-09-03 76° 82° 66° 80° 66–82°
10d · 2026-09-04 67° 68° 66° 76° 66–76°
9d · 2026-09-05 70° 74° 68° 68° 68–74°
8d · 2026-09-06 72° 83° 68° 63° 68° 63–83°
7d · 2026-09-07 72° 76° 66° 64° 66° 64–76°
6d · 2026-09-08 73° 72° 64° 66° 69° 64° 64–73°
5d · 2026-09-09 73° 74° 67° 64° 74° 69° 66° 64–74°
4d · 2026-09-10 73° 72° 68° 67° 74° 66° 73° 66–74°
3d · 2026-09-11 72° 74° 68° 66° 74° 67° 71° 66–74°
2d · 2026-09-12 72° 76° 69° 68° 74° 68° 72° 68–76°
1d · 2026-09-13 74° 75° 70° 66° 73° 68° 74° 66–75°
0d · 2026-09-14 74° 75° 69° 68° 73° 69° 73° 68–75°
actual 71°

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 SFOC1 observations. Archive depth varies by city; receipts exist only for dates the archive watched arrive.