The Spread

Was the forecast right for Charlotte on Tue Aug 18?

Charlotte, North Carolina · daily high temperature in °C · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

13 days out, 4 models put Charlotte's Tue Aug 18 high anywhere from 27° to 35°; by the final call the field had settled to a median of 34°. The day verified at 34° against the ECMWF IFS analysis, with 0.3 mm of precipitation — drizzle.

ICON landed closest, off by 0.1°. GEM ran 2° hot.

13 days out the models said 27–35; it hit 34. ICON led (off 0.1°C); GEM ran 2°C 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 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 Charlotte scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-03 22° 33° 22–33°
14d · 2026-08-04 24° 32° 33° 24–33°
13d · 2026-08-05 27° 35° 35° 31° 27–35°
12d · 2026-08-06 32° 37° 33° 35° 32–37°
11d · 2026-08-07 34° 34° 33° 33° 33–34°
10d · 2026-08-08 33° 36° 35° 33° 33–36°
9d · 2026-08-09 31° 33° 34° 32° 31–34°
8d · 2026-08-10 33° 32° 34° 32° 34° 32–34°
7d · 2026-08-11 33° 32° 34° 31° 35° 31–35°
6d · 2026-08-12 32° 31° 35° 28° 38° 34° 28–38°
5d · 2026-08-13 32° 33° 38° 33° 38° 36° 35° 32–38°
4d · 2026-08-14 33° 34° 35° 30° 38° 34° 33° 30–38°
3d · 2026-08-15 33° 33° 35° 32° 38° 35° 33° 32–38°
2d · 2026-08-16 34° 34° 35° 32° 38° 34° 35° 32–38°
1d · 2026-08-17 34° 35° 34° 36° 35° 34° 34° 34–36°
0d · 2026-08-18 34° 35° 34° 36° 35° 34° 34° 34–36°
actual 34°

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 Charlotte — 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.