KBOS / Wed Sep 23 / OFFICIAL STATION RECORD

Boston, MAHigh ≥ 59°F

FINAL OUTCOMEYESSep 19 · 14:27 UTC

THE FORECAST FIELD

Who takes which side?

0% · NO50%YES · 100%

99%

95%

87%

76%

71%

Consensus

91%

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

WN2YES 84.9¢Risks 84.90u

EPSNO 15.1¢Risks 15.10u

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

WN2 +15.10u · EPS −15.10u

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 2026-09-23T18:00:00+00:00 · UTC

View the forecast data

UTC	AIFS	ICON	GFS	UKMET	GEM	IFS*
2026-09-08T06:00:00+00:00	56.4%	—	—	—	—	—
2026-09-08T12:00:00+00:00	37.5%	—	—	—	—	62.5%
2026-09-08T18:00:00+00:00	90.2%	—	—	—	—	—
2026-09-09T00:00:00+00:00	79.6%	—	—	—	—	88.2%
2026-09-09T06:00:00+00:00	83.8%	—	—	—	—	—
2026-09-09T12:00:00+00:00	91.5%	—	—	—	—	79.6%
2026-09-09T18:00:00+00:00	99.1%	—	—	—	—	—
2026-09-10T00:00:00+00:00	98.7%	—	—	—	—	91.9%
2026-09-10T06:00:00+00:00	83.5%	—	—	—	—	—
2026-09-10T12:00:00+00:00	88.0%	—	—	—	—	91.1%
2026-09-10T18:00:00+00:00	79.6%	—	—	—	—	—
2026-09-11T00:00:00+00:00	75.2%	—	—	—	—	85.4%
2026-09-11T06:00:00+00:00	91.7%	—	—	—	—	—
2026-09-11T12:00:00+00:00	90.0%	—	—	—	—	87.2%
2026-09-11T18:00:00+00:00	66.0%	—	—	—	—	—
2026-09-12T00:00:00+00:00	79.6%	—	—	—	—	88.8%
2026-09-12T06:00:00+00:00	92.1%	—	—	—	—	—
2026-09-12T12:00:00+00:00	74.0%	—	—	—	—	89.3%
2026-09-12T18:00:00+00:00	71.6%	—	—	—	—	—
2026-09-13T00:00:00+00:00	99.8%	—	—	—	—	89.5%
2026-09-13T06:00:00+00:00	96.9%	—	—	—	—	—
2026-09-13T12:00:00+00:00	87.5%	—	—	—	—	93.6%
2026-09-13T18:00:00+00:00	91.1%	—	13.3%	—	—	—
2026-09-14T00:00:00+00:00	87.1%	—	57.6%	—	—	89.2%
2026-09-14T06:00:00+00:00	79.5%	—	61.8%	—	—	—
2026-09-14T12:00:00+00:00	75.3%	—	—	—	—	77.2%
2026-09-14T18:00:00+00:00	60.4%	—	—	—	—	—
2026-09-15T00:00:00+00:00	68.7%	—	61.2%	—	—	87.8%
2026-09-15T06:00:00+00:00	78.4%	—	85.1%	—	—	—
2026-09-15T12:00:00+00:00	76.9%	—	42.2%	—	—	89.0%
2026-09-15T18:00:00+00:00	76.8%	—	70.8%	—	—	—
2026-09-16T00:00:00+00:00	75.1%	—	19.8%	—	—	78.7%
2026-09-16T06:00:00+00:00	80.1%	—	64.8%	—	—	—
2026-09-16T12:00:00+00:00	83.4%	70.2%	83.8%	74.3%	—	72.0%
2026-09-16T18:00:00+00:00	81.6%	—	78.5%	—	—	—
2026-09-17T00:00:00+00:00	75.7%	82.0%	67.0%	92.6%	—	68.3%
2026-09-17T06:00:00+00:00	73.2%	—	76.2%	—	—	—
2026-09-17T12:00:00+00:00	79.5%	83.1%	67.7%	89.0%	—	69.7%
2026-09-17T18:00:00+00:00	83.1%	—	56.2%	—	—	—
2026-09-18T00:00:00+00:00	81.6%	64.1%	67.0%	90.7%	—	67.7%
2026-09-18T06:00:00+00:00	81.6%	49.2%	75.0%	—	—	—
2026-09-18T12:00:00+00:00	81.0%	84.3%	66.2%	88.4%	—	71.4%
2026-09-18T18:00:00+00:00	82.2%	79.9%	76.0%	—	—	—
2026-09-19T00:00:00+00:00	81.6%	81.0%	75.2%	83.9%	—	70.9%
2026-09-19T06:00:00+00:00	77.8%	80.4%	70.6%	—	—	70.6%
2026-09-19T12:00:00+00:00	74.1%	87.6%	67.8%	90.2%	—	71.0%
2026-09-19T18:00:00+00:00	81.7%	87.3%	68.2%	—	—	—
2026-09-20T00:00:00+00:00	80.3%	85.3%	51.9%	85.8%	—	72.9%
2026-09-20T06:00:00+00:00	78.1%	83.0%	72.6%	—	—	72.6%
2026-09-20T12:00:00+00:00	76.5%	75.7%	69.7%	84.9%	—	72.4%
2026-09-20T18:00:00+00:00	78.0%	87.9%	76.3%	—	—	78.7%
2026-09-21T00:00:00+00:00	74.5%	88.1%	72.7%	88.1%	66.9%	78.7%
2026-09-21T06:00:00+00:00	80.2%	89.3%	76.9%	44.4%	—	80.2%
2026-09-21T12:00:00+00:00	80.1%	86.6%	75.8%	90.0%	—	80.1%
2026-09-21T18:00:00+00:00	83.3%	84.0%	84.0%	93.0%	—	82.5%
2026-09-22T00:00:00+00:00	83.4%	86.3%	87.0%	92.9%	83.4%	82.6%
2026-09-22T06:00:00+00:00	83.4%	82.6%	89.1%	92.8%	—	80.0%
2026-09-22T12:00:00+00:00	85.1%	87.4%	89.9%	90.5%	83.5%	82.7%
2026-09-22T18:00:00+00:00	86.8%	93.3%	92.9%	93.3%	—	86.1%
2026-09-23T00:00:00+00:00	87.0%	94.9%	94.9%	96.3%	83.7%	87.0%
2026-09-23T06:00:00+00:00	86.4%	93.0%	96.3%	95.2%	—	82.8%
2026-09-23T12:00:00+00:00	92.3%	93.4%	97.8%	97.4%	89.0%	89.8%
2026-09-23T18:00:00+00:00	7.9%	90.1%	96.6%	96.3%	—	91.4%

THE MODEL BOX SCORE

Forecasts & evidence

MODEL	YES	MEAN	SPREAD σ	INITIALIZATION UTC	BRIER ↓
WeatherNext 2	99%	68.8°F	4.5°F	2026-09-17 12:00	0.0001
AIFS Single	95%	66.0°F	4.7°F	2026-09-19 06:00	0.0029
National Blend	94%	62.0°F	2.2°F	2026-09-19 06:00	0.0032
ICON	87%	63.9°F	4.7°F	2026-09-19 00:00	0.0161
IFS HRES	76%	62.1°F	5.1°F	2026-09-19 00:00	0.0566
IFS Ensemble	71%	60.1°F	2.9°F	2026-09-19 00:00	0.0847
NWS forecast	55%	59.0°F	4.5°F	2026-09-19 02:00	0.2070

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 ≥ 59°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-20260923-TMAX-GE59
Opened Sep 18 · 03:02 UTC

Original listing: Boston high ≥ 59°F · Wed Sep 23

Original prop, full history & receipt ↗