The Spread

Was the forecast right for Washington on Sun Aug 16?

Washington, District of Columbia · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis

13 days out, 4 models put Washington's Sun Aug 16 high anywhere from 81° to 90°; by the final call the field had settled to a median of 79°. The ECMWF IFS analysis says the day verified at 81° with 0.55 in of precipitation — thunderstorms.

UKMO landed closest, off by 1.0°. AIFS ran 4° cold.

13 days out the models said 81–90; it hit 81. UKMO led (off 1.0°F); AIFS ran 4°F 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 Sun Aug 16 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 Washington scoreboard shows them, labelled.

Lead AIFSAIGFSECMWFGEMGFSICONUKMO Range
15d · 2026-08-01 86° 96° 86–96°
14d · 2026-08-02 88° 86° 98° 86–98°
13d · 2026-08-03 90° 81° 83° 82° 81–90°
12d · 2026-08-04 80° 78° 89° 70° 70–89°
11d · 2026-08-05 78° 70° 82° 88° 70–88°
10d · 2026-08-06 95° 80° 83° 88° 80–95°
9d · 2026-08-07 79° 79° 89° 91° 79–91°
8d · 2026-08-08 78° 83° 86° 84° 86° 78–86°
7d · 2026-08-09 76° 90° 90° 80° 80° 76–90°
6d · 2026-08-10 81° 78° 95° 84° 95° 88° 78–95°
5d · 2026-08-11 78° 84° 84° 84° 91° 97° 80° 78–97°
4d · 2026-08-12 88° 89° 85° 80° 97° 94° 91° 80–97°
3d · 2026-08-13 82° 84° 89° 84° 96° 93° 94° 82–96°
2d · 2026-08-14 80° 76° 87° 86° 86° 87° 94° 76–94°
1d · 2026-08-15 78° 77° 78° 83° 81° 79° 82° 77–83°
0d · 2026-08-16 77° 80° 79° 80° 79° 79° 82° 77–82°
actual 81°

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 Washington — 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.