Was the forecast right for Boston on Tue Sep 29?
Boston, Massachusetts · daily high temperature in °F · forecasts from each model's archived runs, verified against the BOS observations
14 days out, 4 models put Boston's Tue Sep 29 high anywhere from 66° to 78°;by the final call, the day before, the field had settled to a median of 65°. The day verified at 66° against the BOS observations — drizzle.
UKMO landed closest, off by 0.6°.
What every model said, at every lead
Daily-high calls for Tue Sep 29 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 · 2026-09-14 | — | 68° | — | — | 56° | — | — | 56–68° |
| 14d · 2026-09-15 | 71° | 69° | 66° | — | 78° | — | — | 66–78° |
| 13d · 2026-09-16 | 67° | 63° | 57° | — | 76° | — | — | 57–76° |
| 12d · 2026-09-17 | 58° | 79° | 67° | — | 61° | — | — | 58–79° |
| 11d · 2026-09-18 | 64° | 67° | 73° | — | 62° | — | — | 62–73° |
| 10d · 2026-09-19 | 67° | 74° | 67° | — | 58° | — | — | 58–74° |
| 9d · 2026-09-20 | 69° | 71° | 64° | 66° | 60° | — | — | 60–71° |
| 8d · 2026-09-21 | 68° | 78° | 59° | 65° | 64° | — | — | 59–78° |
| 7d · 2026-09-22 | 70° | 71° | 60° | 66° | 63° | — | — | 60–71° |
| 6d · 2026-09-23 | 63° | 70° | 62° | 68° | 61° | 61° | 60° | 60–70° |
| 5d · 2026-09-24 | 67° | 63° | 65° | 64° | 63° | 66° | 69° | 63–69° |
| 4d · 2026-09-25 | 66° | 64° | 68° | 63° | 60° | 62° | 62° | 60–68° |
| 3d · 2026-09-26 | 65° | 59° | 62° | 65° | 57° | 63° | 66° | 57–66° |
| 2d · 2026-09-27 | 65° | 59° | 65° | 63° | 62° | 61° | 67° | 59–67° |
| 1d · 2026-09-28 | 65° | 65° | 68° | 68° | 65° | 64° | 67° | 64–68° |
| actual | 66° |
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 BOS observations. 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.