Was the forecast right for Boston on Tue Oct 20?
Boston, Massachusetts · daily high temperature in °F · forecasts from each model's archived runs, verified against the BOS observations
13 days out, 4 models put Boston's Tue Oct 20 high anywhere from 51° to 73°;by the final call, the day before, the field had settled to a median of 60°. The day verified at 62° against the BOS observations — cloudy.
ICON landed closest, off by 0.0°. ECMWF ran 4° cool.
What every model said, at every lead
Daily-high calls for Tue Oct 20 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 · 2026-10-05 | — | 50° | — | — | 62° | — | — | 50–62° |
| 14d · 2026-10-06 | 63° | 63° | — | — | 63° | — | — | 63–63° |
| 13d · 2026-10-07 | 73° | 60° | 51° | — | 57° | — | — | 51–73° |
| 12d · 2026-10-08 | 58° | 58° | 54° | — | 53° | — | — | 53–58° |
| 11d · 2026-10-09 | 67° | 63° | 60° | — | 51° | — | — | 51–67° |
| 10d · 2026-10-10 | 66° | 60° | 68° | — | 54° | — | — | 54–68° |
| 9d · 2026-10-11 | 68° | 69° | 68° | 62° | 66° | — | — | 62–69° |
| 8d · 2026-10-12 | — | 64° | 66° | 62° | 64° | — | — | 62–66° |
| 7d · 2026-10-13 | 66° | 70° | 68° | 63° | 65° | — | — | 63–70° |
| 6d · 2026-10-14 | 61° | 65° | 58° | 62° | 66° | 58° | 60° | 58–66° |
| 5d · 2026-10-15 | 58° | 60° | 58° | 58° | 58° | 59° | 59° | 58–60° |
| 4d · 2026-10-16 | 60° | 58° | 58° | 56° | 59° | 59° | 61° | 56–61° |
| 3d · 2026-10-17 | 60° | 58° | 57° | 58° | 58° | 60° | 59° | 57–60° |
| 2d · 2026-10-18 | 59° | 58° | 57° | 61° | 57° | 62° | 59° | 57–62° |
| 1d · 2026-10-19 | 60° | 60° | 58° | 60° | 58° | 62° | 59° | 58–62° |
| actual | 62° |
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.