Was the forecast right for Boston on Sun Oct 18?
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 Sun Oct 18 high anywhere from 61° to 66°;by the final call, the day before, the field had settled to a median of 53°. The day verified at 53° against the BOS observations — clear.
GEM landed closest, off by 0.3°. ICON ran 2° warm.
What every model said, at every lead
Daily-high calls for Sun Oct 18 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 · 2026-10-03 | — | 66° | — | — | 57° | — | — | 57–66° |
| 14d · 2026-10-04 | 66° | 65° | 61° | — | 61° | — | — | 61–66° |
| 13d · 2026-10-05 | 57° | 58° | 74° | — | 54° | — | — | 54–74° |
| 12d · 2026-10-06 | 51° | 60° | 53° | — | 60° | — | — | 51–60° |
| 11d · 2026-10-07 | 57° | 54° | 56° | — | 74° | — | — | 54–74° |
| 10d · 2026-10-08 | 49° | 57° | 65° | — | 53° | — | — | 49–65° |
| 9d · 2026-10-09 | 46° | 46° | 53° | 46° | 56° | — | — | 46–56° |
| 8d · 2026-10-10 | 51° | 47° | 48° | 44° | 48° | — | — | 44–51° |
| 7d · 2026-10-11 | 59° | 47° | 55° | 52° | 51° | — | — | 47–59° |
| 6d · 2026-10-12 | — | 46° | 55° | 49° | 51° | 46° | 47° | 46–55° |
| 5d · 2026-10-13 | 50° | 60° | 56° | 54° | 59° | 60° | 56° | 50–60° |
| 4d · 2026-10-14 | 55° | 60° | 49° | 56° | 59° | 54° | 51° | 49–60° |
| 3d · 2026-10-15 | 54° | 59° | 53° | 49° | 50° | 53° | 56° | 49–59° |
| 2d · 2026-10-16 | 54° | 55° | 51° | 50° | 49° | 55° | 54° | 49–55° |
| 1d · 2026-10-17 | 54° | 55° | 51° | 53° | 52° | 55° | 52° | 51–55° |
| actual | 53° |
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.