KBOS / Wed Oct 21 / OFFICIAL STATION RECORD

Boston, MAHigh ≤ 51°F

CONSENSUS FORECAST7%Oct 19 · 16:44 UTC

THE FORECAST FIELD

Who takes which side?

0% · NO50%YES · 100%

25%

18%

11%

Consensus

Probabilities derived from each source’s mean and spread. Forecasts may have different initialization times.

HOW A MODEL CONTRACT WORKS

Head-to-head preview

ILLUSTRATIVE · NOT EXECUTED

HRESYES 13.1¢Risks 13.05u

WN2NO 86.9¢Risks 86.95u

100 contracts at the midpoint of these model probabilities. Each contract pays 1u to the winning side.

HRES +86.95u · WN2 −86.95u

These are current forecast comparisons, not locked entries. No credits have been committed. Read the proposed policy →

FOLLOW THE RUNS

Probability history

Recorded Reconstructed

Reconstructed from archived summary forecasts using a shared lead-dependent Gaussian error model. Times are initializations, not verified release times.

AIFS SingleICONGFSUKMETGEMIFS archive

Inspect a forecast 2026-10-19T12:00:00+00:00 · UTC

View the forecast data

UTC	AIFS	ICON	GFS	UKMET	GEM	IFS*
2026-10-06T06:00:00+00:00	66.0%	—	—	—	—	—
2026-10-06T12:00:00+00:00	25.7%	—	—	—	—	42.6%
2026-10-06T18:00:00+00:00	28.8%	—	—	—	—	—
2026-10-07T00:00:00+00:00	35.4%	—	—	—	—	11.5%
2026-10-07T06:00:00+00:00	71.2%	—	—	—	—	—
2026-10-07T12:00:00+00:00	13.7%	—	—	—	—	13.4%
2026-10-07T18:00:00+00:00	3.5%	—	—	—	—	—
2026-10-08T00:00:00+00:00	5.5%	—	—	—	—	12.8%
2026-10-08T06:00:00+00:00	11.0%	—	—	—	—	—
2026-10-08T12:00:00+00:00	13.7%	—	—	—	—	11.8%
2026-10-08T18:00:00+00:00	9.6%	—	—	—	—	—
2026-10-09T00:00:00+00:00	22.0%	—	—	—	—	11.2%
2026-10-09T06:00:00+00:00	13.4%	—	—	—	—	—
2026-10-09T12:00:00+00:00	12.3%	—	—	—	—	8.3%
2026-10-09T18:00:00+00:00	9.3%	—	—	—	—	—
2026-10-10T00:00:00+00:00	8.3%	—	—	—	—	7.1%
2026-10-10T06:00:00+00:00	20.4%	—	—	—	—	—
2026-10-10T12:00:00+00:00	9.5%	—	—	—	—	6.9%
2026-10-10T18:00:00+00:00	21.9%	—	—	—	—	—
2026-10-11T00:00:00+00:00	18.5%	—	—	—	—	10.7%
2026-10-11T06:00:00+00:00	34.2%	—	34.2%	—	—	—
2026-10-11T12:00:00+00:00	39.9%	—	—	—	—	12.2%
2026-10-11T18:00:00+00:00	44.2%	—	—	—	—	—
2026-10-12T00:00:00+00:00	23.6%	—	12.6%	—	—	15.2%
2026-10-12T06:00:00+00:00	6.6%	—	6.9%	—	—	—
2026-10-12T12:00:00+00:00	0.9%	—	—	—	—	10.3%
2026-10-12T18:00:00+00:00	1.2%	—	—	—	—	—
2026-10-13T00:00:00+00:00	1.9%	—	16.1%	—	—	10.7%
2026-10-13T06:00:00+00:00	3.3%	—	2.8%	—	—	—
2026-10-13T12:00:00+00:00	2.3%	—	0.1%	—	—	6.2%
2026-10-13T18:00:00+00:00	0.7%	—	0.1%	—	—	—
2026-10-14T00:00:00+00:00	0.2%	5.2%	1.1%	—	—	10.5%
2026-10-14T06:00:00+00:00	6.0%	—	1.2%	—	—	—
2026-10-14T12:00:00+00:00	26.3%	15.3%	11.5%	6.9%	—	19.4%
2026-10-14T18:00:00+00:00	24.2%	—	7.8%	—	—	—
2026-10-15T00:00:00+00:00	12.4%	17.5%	22.1%	8.7%	—	14.8%
2026-10-15T06:00:00+00:00	8.9%	—	8.9%	—	—	—
2026-10-15T12:00:00+00:00	10.7%	12.5%	16.0%	3.5%	—	16.0%
2026-10-15T18:00:00+00:00	10.9%	—	25.3%	—	—	—
2026-10-16T00:00:00+00:00	8.1%	30.1%	33.0%	5.5%	—	23.0%
2026-10-16T06:00:00+00:00	11.4%	34.9%	24.3%	—	—	—
2026-10-16T12:00:00+00:00	17.3%	28.6%	30.8%	10.8%	—	26.5%
2026-10-16T18:00:00+00:00	15.2%	24.6%	28.1%	—	—	31.9%
2026-10-17T00:00:00+00:00	18.4%	24.1%	27.7%	20.8%	—	28.4%
2026-10-17T06:00:00+00:00	27.9%	24.9%	22.2%	—	—	32.6%
2026-10-17T12:00:00+00:00	35.6%	16.6%	23.7%	32.2%	—	34.7%
2026-10-17T18:00:00+00:00	34.3%	23.8%	22.4%	—	—	38.8%
2026-10-18T00:00:00+00:00	38.5%	21.8%	24.0%	21.8%	—	37.6%
2026-10-18T06:00:00+00:00	36.3%	20.4%	26.5%	—	—	35.3%
2026-10-18T12:00:00+00:00	32.1%	20.4%	32.1%	25.1%	—	36.9%
2026-10-18T18:00:00+00:00	32.6%	15.6%	51.1%	—	—	—
2026-10-19T00:00:00+00:00	32.1%	16.2%	52.2%	28.2%	—	32.1%
2026-10-19T06:00:00+00:00	31.5%	19.8%	36.7%	29.6%	—	32.6%
2026-10-19T12:00:00+00:00	—	—	38.5%	—	14.7%	—

THE MODEL BOX SCORE

Forecasts & evidence

MODEL	YES	MEAN	SPREAD σ	INITIALIZATION UTC	BRIER ↓
IFS HRES	25%	54.3°F	4.1°F	2026-10-19 00:00	Pending
ICON	18%	54.8°F	3.6°F	2026-10-19 00:00	Pending
NWS forecast	15%	55.0°F	3.4°F	2026-10-19 14:00	Pending
National Blend	12%	54.0°F	2.2°F	2026-10-19 06:00	Pending
IFS Ensemble	11%	55.6°F	3.4°F	2026-10-19 00:00	Pending
AIFS Single	8%	57.2°F	4.0°F	2026-10-19 06:00	Pending
WeatherNext 2	1%	58.3°F	3.1°F	2026-10-19 00:00	Pending

Spread is the standard deviation used in the probability approximation. It is not a measured confidence rating. Brier here scores the latest recorded snapshot, not a league deadline.

SETTLEMENT & PROVENANCE

High ≤ 51°F · KBOS

Daily temperature props settle on the ACIS official station record. Inclusive and strict thresholds retain their exact meanings. Provisional observations do not replace the settlement record.

WP-KBOS-20261021-TMAX-LE51
Opened Oct 17 · 07:43 UTC

Original listing: Boston stays cold-for-here: high ≤ 51°F · Wed Oct 21

Original prop, full history & receipt ↗