KBOS / Sun Oct 18 / OFFICIAL STATION RECORD

Boston, MAHigh ≤ 52°F

FINAL OUTCOMENOOct 18 · 07:15 UTC

THE FORECAST FIELD

Who takes which side?

0% · NO50%YES · 100%

63%

49%

20%

12%

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 32.5¢Risks 32.45u

WN2NO 67.5¢Risks 67.55u

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

HRES +67.55u · WN2 −67.55u

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 2026-10-18T18:00:00+00:00 · UTC

View the forecast data

UTC	AIFS	ICON	GFS	UKMET	GEM	IFS*
2026-10-03T06:00:00+00:00	88.0%	—	—	—	—	—
2026-10-03T12:00:00+00:00	86.3%	—	—	—	—	52.7%
2026-10-03T18:00:00+00:00	27.9%	—	—	—	—	—
2026-10-04T00:00:00+00:00	44.2%	—	—	—	—	8.5%
2026-10-04T06:00:00+00:00	21.2%	—	—	—	—	—
2026-10-04T12:00:00+00:00	10.8%	—	—	—	—	12.3%
2026-10-04T18:00:00+00:00	3.5%	—	—	—	—	—
2026-10-05T00:00:00+00:00	31.1%	—	—	—	—	6.9%
2026-10-05T06:00:00+00:00	14.3%	—	—	—	—	—
2026-10-05T12:00:00+00:00	54.8%	—	—	—	—	12.3%
2026-10-05T18:00:00+00:00	38.5%	—	—	—	—	—
2026-10-06T00:00:00+00:00	71.7%	—	—	—	—	12.0%
2026-10-06T06:00:00+00:00	58.5%	—	—	—	—	—
2026-10-06T12:00:00+00:00	48.9%	—	—	—	—	16.5%
2026-10-06T18:00:00+00:00	44.7%	—	—	—	—	—
2026-10-07T00:00:00+00:00	31.6%	—	—	—	—	23.6%
2026-10-07T06:00:00+00:00	21.6%	—	—	—	—	—
2026-10-07T12:00:00+00:00	7.1%	—	—	—	—	23.9%
2026-10-07T18:00:00+00:00	28.9%	—	—	—	—	—
2026-10-08T00:00:00+00:00	19.6%	—	—	—	—	22.0%
2026-10-08T06:00:00+00:00	70.8%	—	—	—	—	—
2026-10-08T12:00:00+00:00	35.6%	—	—	—	—	17.7%
2026-10-08T18:00:00+00:00	77.4%	—	—	—	—	—
2026-10-09T00:00:00+00:00	0.6%	—	—	—	—	20.5%
2026-10-09T06:00:00+00:00	14.4%	—	—	—	—	—
2026-10-09T12:00:00+00:00	67.0%	—	61.4%	—	—	24.2%
2026-10-09T18:00:00+00:00	86.7%	—	—	—	—	—
2026-10-10T00:00:00+00:00	86.8%	—	6.9%	—	—	36.4%
2026-10-10T06:00:00+00:00	84.8%	—	38.0%	—	—	—
2026-10-10T12:00:00+00:00	58.4%	—	13.0%	—	—	36.6%
2026-10-10T18:00:00+00:00	68.5%	—	76.8%	—	—	—
2026-10-11T00:00:00+00:00	88.6%	—	62.0%	—	—	61.3%
2026-10-11T06:00:00+00:00	72.2%	—	86.6%	—	—	—
2026-10-11T12:00:00+00:00	16.6%	69.5%	80.1%	93.5%	—	52.8%
2026-10-11T18:00:00+00:00	15.3%	—	57.1%	—	—	—
2026-10-12T00:00:00+00:00	73.4%	67.0%	52.9%	81.6%	—	56.6%
2026-10-12T06:00:00+00:00	65.3%	—	38.9%	—	—	—
2026-10-12T12:00:00+00:00	64.9%	91.0%	54.6%	85.4%	—	67.7%
2026-10-12T18:00:00+00:00	54.7%	—	60.0%	—	—	—
2026-10-13T00:00:00+00:00	54.0%	46.0%	24.2%	13.6%	—	60.3%
2026-10-13T06:00:00+00:00	68.1%	99.4%	14.8%	—	—	—
2026-10-13T12:00:00+00:00	65.5%	6.6%	7.7%	23.2%	—	50.0%
2026-10-13T18:00:00+00:00	74.7%	13.7%	6.4%	—	—	—
2026-10-14T00:00:00+00:00	74.5%	19.6%	6.5%	33.0%	—	66.2%
2026-10-14T06:00:00+00:00	55.4%	34.2%	6.0%	—	—	—
2026-10-14T12:00:00+00:00	38.2%	43.6%	6.3%	62.7%	—	65.3%
2026-10-14T18:00:00+00:00	30.1%	30.1%	7.0%	—	—	67.4%
2026-10-15T00:00:00+00:00	44.2%	36.6%	7.2%	56.8%	—	65.2%
2026-10-15T06:00:00+00:00	15.8%	42.0%	6.0%	—	—	—
2026-10-15T12:00:00+00:00	35.9%	17.0%	9.8%	22.7%	—	47.9%
2026-10-15T18:00:00+00:00	40.6%	41.6%	34.5%	—	—	—
2026-10-16T00:00:00+00:00	43.5%	20.6%	53.3%	40.3%	—	81.7%
2026-10-16T06:00:00+00:00	34.6%	33.6%	59.0%	99.5%	—	62.2%
2026-10-16T12:00:00+00:00	41.9%	19.9%	44.2%	31.0%	—	52.3%
2026-10-16T18:00:00+00:00	31.4%	19.9%	24.4%	27.3%	—	47.6%
2026-10-17T00:00:00+00:00	34.2%	11.2%	25.6%	35.4%	86.3%	55.0%
2026-10-17T06:00:00+00:00	31.4%	20.0%	24.8%	47.4%	—	57.7%
2026-10-17T12:00:00+00:00	40.7%	7.9%	7.9%	42.0%	84.3%	61.9%
2026-10-17T18:00:00+00:00	35.0%	16.4%	12.4%	35.0%	—	61.0%
2026-10-18T00:00:00+00:00	40.0%	17.2%	4.0%	33.1%	79.8%	60.1%
2026-10-18T06:00:00+00:00	54.5%	24.8%	6.0%	38.1%	—	71.5%
2026-10-18T12:00:00+00:00	46.8%	45.3%	5.2%	43.7%	78.6%	65.4%
2026-10-18T18:00:00+00:00	99.8%	43.4%	8.6%	25.4%	—	—

THE MODEL BOX SCORE

Forecasts & evidence

MODEL	YES	MEAN	SPREAD σ	INITIALIZATION UTC	BRIER ↓
IFS HRES	63%	51.3°F	3.7°F	2026-10-17 12:00	0.3919
IFS Ensemble	49%	52.6°F	3.8°F	2026-10-17 00:00	0.2401
NWS forecast	41%	53.0°F	2.1°F	2026-10-18 03:00	0.1665
ICON	20%	55.4°F	3.5°F	2026-10-17 12:00	0.0420
AIFS Single	12%	57.2°F	3.9°F	2026-10-17 18:00	0.0135
WeatherNext 2	2%	58.3°F	2.9°F	2026-10-17 18:00	0.0005
National Blend	1%	55.0°F	1.1°F	2026-10-18 00:00	0.0002

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 ≤ 52°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-20261018-TMAX-LE52
Opened Oct 14 · 10:31 UTC

Original listing: Boston stays cold-for-here: high ≤ 52°F · Sun Oct 18

Original prop, full history & receipt ↗