The Spread

Was the forecast right for Los Angeles on Thu Aug 20?

Los Angeles, California · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

13 days out, 4 models put Los Angeles's Thu Aug 20 high anywhere from 26° to 29°; by the final call the field had settled to a median of 33°. The day verified at 35° against the ECMWF IFS analysis — cloudy.

GFS landed closest, off by 0.9°. AIGFS ran 8° cold.

13 days out the models said 26–29; it hit 35. GFS led (off 0.9°C); AIGFS ran 8°C cold.
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 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 Los Angeles scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-05 24° 29° 24–29°
14d · 2026-08-06 26° 30° 31° 26–31°
13d · 2026-08-07 26° 26° 29° 29° 26–29°
12d · 2026-08-08 31° 26° 28° 34° 26–34°
11d · 2026-08-09 29° 24° 26° 35° 24–35°
10d · 2026-08-10 27° 28° 33° 30° 27–33°
9d · 2026-08-11 30° 28° 26° 30° 26–30°
8d · 2026-08-12 33° 29° 27° 31° 31° 27–33°
7d · 2026-08-13 32° 27° 32° 34° 32° 27–34°
6d · 2026-08-14 32° 26° 30° 35° 35° 32° 26–35°
5d · 2026-08-15 31° 27° 37° 36° 35° 33° 31° 27–37°
4d · 2026-08-16 31° 26° 34° 35° 36° 32° 33° 26–36°
3d · 2026-08-17 31° 26° 35° 34° 35° 31° 34° 26–35°
2d · 2026-08-18 30° 26° 35° 34° 35° 31° 33° 26–35°
1d · 2026-08-19 29° 26° 33° 33° 34° 31° 35° 26–35°
0d · 2026-08-20 29° 27° 33° 33° 34° 30° 34° 27–34°
actual 35°

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 Los Angeles — 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). Archive depth varies by city; receipts exist only for dates the archive watched arrive.