KBOS / Thu Oct 22 / OFFICIAL STATION RECORD

Boston, MAHigh ≤ 50°F

CONSENSUS FORECAST2%Oct 18 · 13:18 UTC

THE FORECAST FIELD

Who takes which side?

0% · NO50%YES · 100%

10%

<1%

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

AIFSYES 5.1¢Risks 1.28u

WN2NO 94.9¢Risks 23.72u

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

AIFS +23.72u · WN2 −23.72u

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 SingleICONGFSUKMETIFS archive

Inspect a forecast 2026-10-19T06:00:00+00:00 · UTC

View the forecast data

UTC	AIFS	ICON	GFS	UKMET	IFS*
2026-10-07T06:00:00+00:00	98.4%	—	—	—	—
2026-10-07T12:00:00+00:00	76.0%	—	—	—	39.0%
2026-10-07T18:00:00+00:00	4.4%	—	—	—	—
2026-10-08T00:00:00+00:00	27.4%	—	—	—	9.8%
2026-10-08T06:00:00+00:00	5.8%	—	—	—	—
2026-10-08T12:00:00+00:00	14.3%	—	—	—	8.5%
2026-10-08T18:00:00+00:00	2.9%	—	—	—	—
2026-10-09T00:00:00+00:00	7.7%	—	—	—	8.3%
2026-10-09T06:00:00+00:00	2.9%	—	—	—	—
2026-10-09T12:00:00+00:00	2.2%	—	—	—	5.3%
2026-10-09T18:00:00+00:00	5.8%	—	—	—	—
2026-10-10T00:00:00+00:00	1.5%	—	—	—	6.1%
2026-10-10T06:00:00+00:00	11.0%	—	—	—	—
2026-10-10T12:00:00+00:00	23.6%	—	—	—	5.3%
2026-10-10T18:00:00+00:00	41.0%	—	—	—	—
2026-10-11T00:00:00+00:00	33.5%	—	—	—	8.1%
2026-10-11T06:00:00+00:00	31.1%	—	—	—	—
2026-10-11T12:00:00+00:00	17.8%	—	—	—	7.6%
2026-10-11T18:00:00+00:00	33.2%	—	—	—	—
2026-10-12T00:00:00+00:00	36.0%	—	—	—	7.2%
2026-10-12T06:00:00+00:00	4.9%	—	55.6%	—	—
2026-10-12T12:00:00+00:00	0.5%	—	—	—	10.3%
2026-10-12T18:00:00+00:00	1.4%	—	—	—	—
2026-10-13T00:00:00+00:00	0.5%	—	—	—	11.4%
2026-10-13T06:00:00+00:00	1.9%	—	—	—	—
2026-10-13T12:00:00+00:00	0.8%	—	—	—	6.6%
2026-10-13T18:00:00+00:00	0.1%	—	0.1%	—	—
2026-10-14T00:00:00+00:00	0.1%	—	0.5%	—	9.6%
2026-10-14T06:00:00+00:00	8.4%	—	0.5%	—	—
2026-10-14T12:00:00+00:00	14.4%	—	5.7%	—	21.2%
2026-10-14T18:00:00+00:00	20.3%	—	11.2%	—	—
2026-10-15T00:00:00+00:00	12.1%	39.3%	25.4%	—	21.8%
2026-10-15T06:00:00+00:00	14.6%	—	27.8%	—	—
2026-10-15T12:00:00+00:00	10.5%	38.2%	36.9%	18.9%	24.1%
2026-10-15T18:00:00+00:00	16.1%	—	32.0%	—	—
2026-10-16T00:00:00+00:00	9.0%	5.7%	42.0%	18.4%	24.3%
2026-10-16T06:00:00+00:00	19.4%	—	34.7%	—	—
2026-10-16T12:00:00+00:00	35.1%	33.7%	34.4%	20.5%	23.4%
2026-10-16T18:00:00+00:00	39.2%	—	32.6%	—	—
2026-10-17T00:00:00+00:00	35.2%	27.4%	8.1%	5.3%	23.0%
2026-10-17T06:00:00+00:00	17.9%	49.2%	4.7%	—	21.2%
2026-10-17T12:00:00+00:00	29.3%	10.8%	1.6%	2.1%	17.3%
2026-10-17T18:00:00+00:00	22.6%	19.0%	1.4%	—	8.8%
2026-10-18T00:00:00+00:00	33.8%	9.0%	0.2%	0.5%	7.0%
2026-10-18T06:00:00+00:00	28.7%	12.1%	0.1%	—	6.3%
2026-10-18T12:00:00+00:00	29.7%	2.0%	0.1%	0.4%	3.0%
2026-10-18T18:00:00+00:00	13.7%	0.0%	1.5%	—	—
2026-10-19T00:00:00+00:00	3.0%	0.0%	0.2%	0.3%	0.9%
2026-10-19T06:00:00+00:00	—	0.4%	2.0%	—	—

THE MODEL BOX SCORE

Forecasts & evidence

MODEL	YES	MEAN	SPREAD σ	INITIALIZATION UTC	BRIER ↓
AIFS Single	10%	56.5°F	4.6°F	2026-10-18 00:00	Pending
IFS Ensemble	8%	57.3°F	4.8°F	2026-10-18 00:00	Pending
NWS forecast	7%	57.0°F	4.5°F	2026-10-18 03:00	Pending
ICON	6%	58.3°F	4.9°F	2026-10-18 00:00	Pending
IFS HRES	2%	61.4°F	5.0°F	2026-10-18 00:00	Pending
National Blend	1%	58.0°F	3.4°F	2026-10-18 06:00	Pending
WeatherNext 2	<1%	59.8°F	3.7°F	2026-10-18 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 ≤ 50°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-20261022-TMAX-LE50
Opened Oct 18 · 08:00 UTC

Original listing: Boston stays cold-for-here: high ≤ 50°F · Thu Oct 22

Original prop, full history & receipt ↗