Was the forecast right for Boston on Fri Aug 14?
Boston, Massachusetts · daily high temperature in °F · forecasts from each model's archived runs, verified against the ECMWF IFS analysis
13 days out, 4 models put Boston's Fri Aug 14 high anywhere from 65° to 81°; by the final call the field had settled to a median of 82°. The ECMWF IFS analysis says the day verified at 82° — cloudy.
ECMWF landed closest, off by 0.3°. GFS ran 4° hot.
What every model said, at every lead
Daily-high calls for Fri Aug 14 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 Boston scoreboard shows them, labelled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-07-30 | — | 79° | — | — | 71° | — | — | 71–79° |
| 14d · 2026-07-31 | 87° | 72° | — | — | 80° | — | — | 72–87° |
| 13d · 2026-08-01 | 77° | 75° | 81° | — | 65° | — | — | 65–81° |
| 12d · 2026-08-02 | 77° | 80° | 80° | — | 71° | — | — | 71–80° |
| 11d · 2026-08-03 | 80° | 69° | 81° | — | 72° | — | — | 69–81° |
| 10d · 2026-08-04 | 76° | 82° | 78° | — | 78° | — | — | 76–82° |
| 9d · 2026-08-05 | 78° | 79° | 88° | — | 82° | — | — | 78–88° |
| 8d · 2026-08-06 | 78° | 81° | 81° | 80° | 80° | — | — | 78–81° |
| 7d · 2026-08-07 | 78° | 77° | 85° | 77° | 75° | — | — | 75–85° |
| 6d · 2026-08-08 | 78° | 81° | 80° | 74° | 80° | 85° | — | 74–85° |
| 5d · 2026-08-09 | 78° | 80° | 81° | 81° | 77° | 81° | 84° | 77–84° |
| 4d · 2026-08-10 | 80° | 80° | 89° | 79° | 75° | 89° | 83° | 75–89° |
| 3d · 2026-08-11 | 80° | 81° | 84° | 79° | 80° | 85° | 79° | 79–85° |
| 2d · 2026-08-12 | 80° | 80° | 86° | 83° | 81° | 82° | 83° | 80–86° |
| 1d · 2026-08-13 | 80° | 81° | 82° | 82° | 83° | 81° | 82° | 80–83° |
| 0d · 2026-08-14 | 80° | 83° | 81° | 84° | 85° | 82° | 82° | 80–85° |
| actual | 82° |
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 Boston — 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.