Was the forecast right for Boston on Thu Sep 24?
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 Thu Sep 24 high anywhere from 59° to 70°;by the final call, the day before, the field had settled to a median of 62°. The day verified at 65° against the BOS observations — cloudy.
GEM landed closest, off by 0.6°. GFS ran 5° cool.
What every model said, at every lead
Daily-high calls for Thu Sep 24 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 · 2026-09-09 | — | 54° | — | — | 68° | — | — | 54–68° |
| 14d · 2026-09-10 | 70° | 68° | 59° | — | 66° | — | — | 59–70° |
| 13d · 2026-09-11 | 68° | 74° | 72° | — | 59° | — | — | 59–74° |
| 12d · 2026-09-12 | 62° | 75° | 61° | — | 58° | — | — | 58–75° |
| 11d · 2026-09-13 | 70° | 73° | 61° | — | 60° | — | — | 60–73° |
| 10d · 2026-09-14 | 62° | 67° | 66° | — | 61° | — | — | 61–67° |
| 9d · 2026-09-15 | 65° | 76° | 64° | 67° | 68° | — | — | 64–76° |
| 8d · 2026-09-16 | 63° | 55° | 61° | 65° | 70° | — | — | 55–70° |
| 7d · 2026-09-17 | 63° | 52° | 61° | 60° | 60° | — | — | 52–63° |
| 6d · 2026-09-18 | 62° | 57° | 62° | 60° | 59° | 63° | 63° | 57–63° |
| 5d · 2026-09-19 | 64° | 59° | 60° | 60° | 60° | 63° | 62° | 59–64° |
| 4d · 2026-09-20 | 63° | 60° | 61° | 60° | 60° | 62° | 61° | 60–63° |
| 3d · 2026-09-21 | 63° | 58° | 60° | 63° | 60° | 62° | 62° | 58–63° |
| 2d · 2026-09-22 | 62° | 60° | 60° | 63° | 60° | 62° | 62° | 60–63° |
| 1d · 2026-09-23 | 63° | 61° | 61° | 64° | 60° | 62° | 62° | 60–64° |
| actual | 65° |
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.