The Spread

Was the forecast right for San Francisco on Thu Aug 13?

San Francisco, California · daily high temperature in °F · forecasts from each model's archived runs, verified against ERA5

13 days out, 4 models put San Francisco's Thu Aug 13 high anywhere from 65° to 72°; by the final call the field had settled to a median of 66°. ERA5 says the day verified at 66° — drizzle.

ECMWF landed closest, off by 0.3°. AIGFS ran 3° hot.

13 days out the models said 65–72; it hit 66. ECMWF led (off 0.3°F); AIGFS ran 3°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 Thu Aug 13 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 · 2026-07-29 71° 68° 68–71°
14d · 2026-07-30 68° 71° 74° 68–74°
13d · 2026-07-31 72° 66° 65° 72° 65–72°
12d · 2026-08-01 66° 74° 67° 81° 66–81°
11d · 2026-08-02 68° 79° 67° 69° 67–79°
10d · 2026-08-03 66° 75° 67° 78° 66–78°
9d · 2026-08-04 66° 72° 69° 68° 66–72°
8d · 2026-08-05 67° 70° 68° 69° 72° 67–72°
7d · 2026-08-06 68° 68° 69° 67° 70° 67–70°
6d · 2026-08-07 68° 73° 69° 67° 73° 66° 66–73°
5d · 2026-08-08 66° 73° 72° 71° 73° 66° 68° 66–73°
4d · 2026-08-09 64° 73° 71° 70° 69° 67° 68° 64–73°
3d · 2026-08-10 64° 69° 71° 65° 69° 65° 67° 64–71°
2d · 2026-08-11 64° 66° 65° 62° 66° 64° 65° 62–66°
1d · 2026-08-12 64° 67° 66° 65° 65° 64° 67° 64–67°
0d · 2026-08-13 65° 69° 66° 65° 67° 64° 66° 64–69°
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.