Was the forecast right for Boston on Mon Oct 26?
Boston, Massachusetts · daily high temperature in °C · forecasts from each model's archived runs, verified against the BOS observations
13 days out, 4 models put Boston's Mon Oct 26 high anywhere from 11° to 19°;by the final call, the day before, the field had settled to a median of 20°. The day verified at 23° against the BOS observations — cloudy.
GEM landed closest, off by 1.4°. ECMWF ran 5° cool.
What every model said, at every lead
Daily-high calls for Mon Oct 26 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, labeled.
| Lead | AIFS | AIGFS | ECMWF | GEM | GFS | ICON | UKMO | Range |
|---|---|---|---|---|---|---|---|---|
| 15d · 2026-10-11 | — | 16° | — | — | 12° | — | — | 12–16° |
| 14d · 2026-10-12 | — | 17° | 16° | — | 12° | — | — | 12–17° |
| 13d · 2026-10-13 | 15° | 19° | 12° | — | 11° | — | — | 11–19° |
| 12d · 2026-10-14 | 12° | 15° | 15° | — | 19° | — | — | 12–19° |
| 11d · 2026-10-15 | 16° | 20° | 12° | — | 11° | — | — | 11–20° |
| 10d · 2026-10-16 | 16° | 12° | 15° | — | 13° | — | — | 12–16° |
| 9d · 2026-10-17 | 19° | 12° | 19° | 16° | 16° | — | — | 12–19° |
| 8d · 2026-10-18 | 20° | 21° | 19° | 16° | 17° | — | — | 16–21° |
| 7d · 2026-10-19 | 20° | 22° | 20° | 17° | 19° | — | — | 17–22° |
| 6d · 2026-10-20 | 19° | 22° | 18° | 18° | 19° | 21° | 18° | 18–22° |
| 5d · 2026-10-21 | 19° | 21° | 18° | 16° | 20° | 21° | 17° | 16–21° |
| 4d · 2026-10-22 | 20° | 21° | 19° | 17° | 20° | 22° | 19° | 17–22° |
| 3d · 2026-10-23 | 20° | 21° | 18° | 20° | 20° | 22° | 19° | 18–22° |
| 2d · 2026-10-24 | 19° | 20° | 18° | 21° | 20° | 21° | 19° | 18–21° |
| 1d · 2026-10-25 | 19° | 21° | 18° | 21° | 20° | 21° | 19° | 18–21° |
| actual | 23° |
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 day was verified, usually 2 days after the date; a correction published after that is not carried into it. Archive depth varies by city; verified days exist only for dates the archive watched arrive.