Was the forecast right for Boston on Mon Oct 19?
Boston, Massachusetts · daily high temperature in °C · forecasts from each model's archived runs, verified against the BOS observations
14 days out, 4 models put Boston's Mon Oct 19 high anywhere from 10° to 25°;by the final call, the day before, the field had settled to a median of 14°. The day verified at 13° against the BOS observations — clear.
ICON landed closest, off by 0.3°. GEM ran 1° warm.
What every model said, at every lead
Daily-high calls for Mon Oct 19 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 · 2026-10-04 | — | 13° | — | — | 14° | — | — | 13–14° |
| 14d · 2026-10-05 | 17° | 12° | 25° | — | 10° | — | — | 10–25° |
| 13d · 2026-10-06 | 12° | 15° | 15° | — | 18° | — | — | 12–18° |
| 12d · 2026-10-07 | 20° | 14° | 12° | — | 18° | — | — | 12–20° |
| 11d · 2026-10-08 | 8° | 14° | 13° | — | 16° | — | — | 8–16° |
| 10d · 2026-10-09 | 15° | 13° | 18° | — | 13° | — | — | 13–18° |
| 9d · 2026-10-10 | 19° | 10° | 14° | 9° | 9° | — | — | 9–19° |
| 8d · 2026-10-11 | 18° | 15° | 18° | 15° | 17° | — | — | 15–18° |
| 7d · 2026-10-12 | — | 10° | 18° | 15° | 16° | — | — | 10–18° |
| 6d · 2026-10-13 | 17° | 20° | 18° | 17° | 18° | 20° | 18° | 17–20° |
| 5d · 2026-10-14 | 16° | 20° | 12° | 17° | 18° | 17° | 13° | 12–20° |
| 4d · 2026-10-15 | 14° | 18° | 13° | 14° | 13° | 15° | 17° | 13–18° |
| 3d · 2026-10-16 | 14° | 14° | 13° | 13° | 13° | 15° | 16° | 13–16° |
| 2d · 2026-10-17 | 14° | 14° | 12° | 14° | 12° | 14° | 13° | 12–14° |
| 1d · 2026-10-18 | 14° | 14° | 12° | 14° | 12° | 14° | 13° | 12–14° |
| actual | 13° |
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.