KSTL / Thu Oct 1 / OFFICIAL STATION RECORD

St. Louis, MOHigh ≥ 90°F

FINAL OUTCOMEYESOct 01 · 06:57 UTC

THE FORECAST FIELD

Who takes which side?

0% · NO50%YES · 100%

56%

49%

43%

Consensus

11%

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 28.5¢Risks 28.50u

ICONNO 71.5¢Risks 71.50u

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

AIFS +71.50u · ICON −71.50u

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 2026-10-01T18:00:00+00:00 · UTC

View the forecast data

UTC	AIFS	ICON	GFS	UKMET	GEM	IFS*
2026-09-16T12:00:00+00:00	0.0%	—	—	—	—	0.1%
2026-09-16T18:00:00+00:00	2.9%	—	—	—	—	—
2026-09-17T00:00:00+00:00	0.1%	—	—	—	—	7.7%
2026-09-17T06:00:00+00:00	0.9%	—	—	—	—	—
2026-09-17T12:00:00+00:00	12.8%	—	—	—	—	7.7%
2026-09-17T18:00:00+00:00	6.1%	—	—	—	—	—
2026-09-18T00:00:00+00:00	0.6%	—	—	—	—	10.8%
2026-09-18T06:00:00+00:00	0.6%	—	—	—	—	—
2026-09-18T12:00:00+00:00	2.8%	—	—	—	—	5.9%
2026-09-18T18:00:00+00:00	22.0%	—	—	—	—	—
2026-09-19T00:00:00+00:00	4.0%	—	—	—	—	4.9%
2026-09-19T06:00:00+00:00	0.7%	—	—	—	—	—
2026-09-19T12:00:00+00:00	0.1%	—	—	—	—	4.5%
2026-09-19T18:00:00+00:00	0.1%	—	—	—	—	—
2026-09-20T00:00:00+00:00	0.1%	—	—	—	—	3.2%
2026-09-20T06:00:00+00:00	0.1%	—	—	—	—	—
2026-09-20T12:00:00+00:00	1.2%	—	—	—	—	3.3%
2026-09-20T18:00:00+00:00	0.5%	—	—	—	—	—
2026-09-21T00:00:00+00:00	0.1%	—	—	—	—	6.6%
2026-09-21T06:00:00+00:00	32.2%	—	0.2%	—	—	—
2026-09-21T12:00:00+00:00	10.5%	—	—	—	—	8.2%
2026-09-21T18:00:00+00:00	0.1%	—	—	—	—	—
2026-09-22T00:00:00+00:00	2.7%	—	2.8%	—	—	5.6%
2026-09-22T06:00:00+00:00	0.5%	—	20.1%	—	—	—
2026-09-22T12:00:00+00:00	1.3%	—	—	—	—	1.6%
2026-09-22T18:00:00+00:00	1.2%	—	—	—	—	—
2026-09-23T00:00:00+00:00	2.3%	—	0.2%	—	—	0.5%
2026-09-23T06:00:00+00:00	0.1%	—	0.0%	—	—	—
2026-09-23T12:00:00+00:00	0.3%	—	0.0%	—	—	0.6%
2026-09-23T18:00:00+00:00	19.4%	—	0.9%	—	—	—
2026-09-24T00:00:00+00:00	36.7%	0.0%	5.0%	—	—	1.5%
2026-09-24T06:00:00+00:00	37.8%	—	1.6%	—	—	—
2026-09-24T12:00:00+00:00	52.8%	—	47.2%	0.0%	—	3.2%
2026-09-24T18:00:00+00:00	49.3%	—	71.1%	—	—	—
2026-09-25T00:00:00+00:00	34.3%	1.5%	39.9%	24.9%	—	4.1%
2026-09-25T06:00:00+00:00	39.6%	—	4.6%	—	—	—
2026-09-25T12:00:00+00:00	1.8%	28.9%	30.3%	3.0%	—	9.7%
2026-09-25T18:00:00+00:00	0.0%	—	2.1%	—	—	—
2026-09-26T00:00:00+00:00	21.8%	6.9%	4.9%	4.5%	—	3.1%
2026-09-26T06:00:00+00:00	30.4%	—	4.1%	—	—	—
2026-09-26T12:00:00+00:00	18.9%	14.8%	1.9%	0.2%	—	10.1%
2026-09-26T18:00:00+00:00	8.8%	22.6%	1.5%	—	—	—
2026-09-27T00:00:00+00:00	27.7%	0.3%	2.9%	0.7%	—	25.5%
2026-09-27T06:00:00+00:00	19.6%	0.1%	1.6%	—	—	—
2026-09-27T12:00:00+00:00	33.9%	0.1%	1.0%	0.3%	—	5.0%
2026-09-27T18:00:00+00:00	37.0%	11.8%	18.4%	—	—	6.1%
2026-09-28T00:00:00+00:00	28.7%	0.1%	3.5%	0.0%	—	14.2%
2026-09-28T06:00:00+00:00	25.7%	5.1%	48.0%	—	—	—
2026-09-28T12:00:00+00:00	26.8%	2.1%	52.1%	0.1%	—	30.3%
2026-09-28T18:00:00+00:00	30.7%	15.6%	50.0%	—	—	—
2026-09-29T00:00:00+00:00	24.7%	4.5%	64.9%	0.7%	—	19.8%
2026-09-29T06:00:00+00:00	16.1%	0.4%	52.2%	0.7%	—	16.8%
2026-09-29T12:00:00+00:00	13.4%	0.0%	55.8%	0.5%	7.6%	10.5%
2026-09-29T18:00:00+00:00	19.1%	1.2%	29.3%	0.2%	—	—
2026-09-30T00:00:00+00:00	28.7%	3.7%	16.6%	0.2%	26.6%	27.6%
2026-09-30T06:00:00+00:00	19.1%	0.2%	32.5%	0.1%	—	0.0%
2026-09-30T12:00:00+00:00	12.7%	1.1%	11.3%	0.6%	55.4%	6.1%
2026-09-30T18:00:00+00:00	12.4%	0.1%	0.2%	4.0%	—	5.4%
2026-10-01T00:00:00+00:00	2.5%	0.1%	0.0%	19.1%	62.8%	3.5%
2026-10-01T06:00:00+00:00	4.1%	6.0%	1.3%	41.0%	—	16.2%
2026-10-01T12:00:00+00:00	10.2%	48.4%	57.9%	15.2%	48.4%	37.6%
2026-10-01T18:00:00+00:00	0.0%	53.3%	64.5%	64.5%	—	30.9%

THE MODEL BOX SCORE

Forecasts & evidence

MODEL	YES	MEAN	SPREAD σ	INITIALIZATION UTC	BRIER ↓
AIFS Single	56%	90.1°F	4.0°F	2026-09-30 18:00	0.1945
WeatherNext 2	49%	89.4°F	3.4°F	2026-09-30 18:00	0.2621
IFS Ensemble	43%	88.8°F	3.8°F	2026-09-30 00:00	0.3283
National Blend	29%	87.1°F	4.4°F	2026-10-01 00:00	0.4984
NWS forecast	6%	86.0°F	2.2°F	2026-10-01 02:00	0.8911
IFS HRES	2%	82.0°F	3.7°F	2026-09-30 12:00	0.9565
ICON	1%	81.4°F	3.5°F	2026-09-30 12:00	0.9781

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 ≥ 90°F · KSTL

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-KSTL-20261001-TMAX-GE90
Opened Sep 24 · 07:28 UTC

Original listing: A 90° day in St. Louis · Thu Oct 1

Original prop, full history & receipt ↗