The Spread

Was the forecast right for Los Angeles on Tue Aug 18?

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 Tue Aug 18 high anywhere from 24° to 32°; by the final call the field had settled to a median of 32°. The day verified at 35° against the ECMWF IFS analysis — cloudy.

GFS landed closest, off by 0.7°. AIGFS ran 7° cold.

13 days out the models said 24–32; it hit 35. GFS led (off 0.7°C); AIGFS ran 7°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 Tue Aug 18 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 · 2026-08-03 28° 36° 28–36°
14d · 2026-08-04 28° 23° 31° 23–31°
13d · 2026-08-05 26° 24° 30° 32° 24–32°
12d · 2026-08-06 28° 26° 28° 30° 26–30°
11d · 2026-08-07 27° 26° 32° 32° 26–32°
10d · 2026-08-08 33° 26° 30° 32° 26–33°
9d · 2026-08-09 26° 24° 28° 31° 24–31°
8d · 2026-08-10 28° 29° 33° 32° 31° 28–33°
7d · 2026-08-11 31° 28° 28° 31° 33° 28–33°
6d · 2026-08-12 32° 29° 28° 32° 33° 34° 28–34°
5d · 2026-08-13 32° 27° 32° 32° 34° 30° 33° 27–34°
4d · 2026-08-14 31° 27° 32° 32° 35° 31° 31° 27–35°
3d · 2026-08-15 31° 28° 32° 33° 35° 31° 32° 28–35°
2d · 2026-08-16 30° 27° 32° 32° 34° 31° 31° 27–34°
1d · 2026-08-17 30° 27° 33° 32° 34° 30° 31° 27–34°
0d · 2026-08-18 30° 27° 33° 32° 34° 30° 32° 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.