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
14 days out, 4 models put Boston's Fri Aug 14 high anywhere from 70° to 80°;by the final call, the day before, the field had settled to a median of 82°. The day verified at 82° against the ECMWF IFS analysis — cloudy.
ECMWF landed closest, off by 0.3°. GFS ran 2° warm.
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 | — | 88° | — | — | 79° | — | — | 79–88° |
| 14d · 2026-07-31 | 76° | 80° | 74° | — | 70° | — | — | 70–80° |
| 13d · 2026-08-01 | 78° | 85° | 74° | — | 68° | — | — | 68–85° |
| 12d · 2026-08-02 | 77° | 93° | 70° | — | 77° | — | — | 70–93° |
| 11d · 2026-08-03 | 74° | 82° | 85° | — | 74° | — | — | 74–85° |
| 10d · 2026-08-04 | 77° | 82° | 83° | — | 74° | — | — | 74–83° |
| 9d · 2026-08-05 | 82° | 78° | 87° | 80° | 81° | — | — | 78–87° |
| 8d · 2026-08-06 | 78° | 78° | 85° | 79° | 78° | — | — | 78–85° |
| 7d · 2026-08-07 | 81° | 77° | 82° | 78° | 74° | — | — | 74–82° |
| 6d · 2026-08-08 | 80° | 80° | 79° | 74° | 78° | 82° | 84° | 74–84° |
| 5d · 2026-08-09 | 80° | 79° | 79° | 79° | 75° | 80° | 81° | 75–81° |
| 4d · 2026-08-10 | 80° | 80° | 88° | 78° | 80° | 81° | 82° | 78–88° |
| 3d · 2026-08-11 | 80° | 83° | 85° | 83° | 80° | 83° | 82° | 80–85° |
| 2d · 2026-08-12 | 81° | 82° | 82° | 82° | 82° | 82° | 83° | 81–83° |
| 1d · 2026-08-13 | 80° | 82° | 82° | 84° | 84° | 83° | 82° | 80–84° |
| 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). The actual values are the ones in hand when this receipt was settled, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; receipts exist only for dates the archive watched arrive.