Highest temperature in Chicago on Oct 5, 2026: PBE moves “63° or below” down to 21% from 34%
New forecast guidance reached the model between 14:00 UTC and 17:00 UTC on Oct 4. Same model version, later data cutoff: here is exactly which inputs changed.
Photo: J. Crocker · Attribution · Wikimedia Commons
63° or below · pbe-weather-maxtemp@1.1.0 · 14:00 UTC → 17:00 UTC
Highest temperature in Chicago on Oct 5, 2026?
63° or below · RESOLVED
- UPDATE · Oct 5 07:22Z PBE 8% pbe-weather-maxtemp-intraday@2.1.0 · data cutoff Oct 5 07:22Z
Quick read
- pbe-weather-maxtemp@1.1.0 moved “63° or below” from 34% to 21% (−13 pts).
- Later data cutoff: Oct 4 11:00Z → Oct 4 17:00Z; same model version, so the move reflects inputs, not a model change.
- Primary inputs changed: GFS MOS forecast high, National Blend of Models forecast high.
- A comparable market observation was not captured with both snapshots, so no market move is stated.
What changed in the inputs
Between the snapshot captured at Oct 4 14:00Z (data cutoff Oct 4 11:00Z) and the one at Oct 4 17:00Z (cutoff Oct 4 17:00Z), the same model version — pbe-weather-maxtemp@1.1.0 — moved “63° or below” from 34% to 21%. The model inputs that changed: GFS MOS forecast high from 68°F to 69°F; National Blend of Models forecast high from 64°F to 65°F.
| Input | Before | After | Primary |
|---|---|---|---|
| Guidance lead time | 24h | 18h | — |
| GFS MOS forecast high | 68°F | 69°F | yes |
| National Blend of Models forecast high | 64°F | 65°F | yes |
This page reports which stored inputs differ between two immutable forecasts. It does not claim why the underlying weather guidance changed.
The forecast path
Data table
| Time (UTC) | Source | Value % |
|---|---|---|
| Oct 4 14:00Z | PBE pbe-weather-maxtemp@1.1.0 | 34 |
| Oct 4 14:15Z | Kalshi mid | 3 |
| Oct 4 14:30Z | Kalshi mid | 2 |
| Oct 4 15:00Z | Kalshi mid | 2 |
| Oct 4 15:15Z | Kalshi mid | 2 |
| Oct 4 16:00Z | Kalshi mid | 2 |
| Oct 4 16:45Z | Kalshi mid | 2 |
| Oct 4 17:00Z | PBE pbe-weather-maxtemp@1.1.0 | 21 |
| Oct 4 17:00Z | Kalshi mid | 2 |
A comparable market observation was not captured with both snapshots, so no market move is stated.
The two snapshots
| Earlier | Later | |
|---|---|---|
| Captured | Oct 4 14:00Z | Oct 4 17:00Z |
| Data cutoff | Oct 4 11:00Z | Oct 4 17:00Z |
| Guidance runs | NWS GFS MOS 2026-10-04T06Z, NWS National Blend of Models 2026-10-04T06Z | NWS GFS MOS 2026-10-04T12Z, NWS National Blend of Models 2026-10-04T12Z |
| PBE | 34% | 21% |
| Market at capture | — | 2% |
Evidence & method
What this story is based on. Every value above was read from these immutable records.
- Model
- pbe-weather-maxtemp@1.1.0 · RESEARCH
- Snapshot
- 381c8597-b9c1-465d-871d-5f286ae3a87a
- Compared with
- 52063be0-81f2-4f20-b915-2fbc430a0779
- Captured
- Oct 4 17:00Z
- Data cutoff
- Oct 4 17:00Z
- Market observation
- 2% · captured with the snapshot
- Source families
- NOAA/NWS via Iowa Environmental Mesonet archive · NOAA Regional Climate Centers ACIS · NOAA/NWS api.weather.gov
- Resolves on
- The Weather Company (weather.com/kalshi) — The Weather Company daily maximum temperature for CLIMDW (weather.com/kalshi)
- Independent check
- NWS Daily Climate Report CLIMDW (WFO LOT); NOAA RCC-ACIS USW00014819
- Measurement
- Maximum temperature for the climate day 2026-10-05, 00:00-24:00 local standard time (UTC-6)
- Rounding
- Whole degrees Fahrenheit as reported; preliminary values may differ by rounding/conversion
- Exceptions
- Preliminary data may be revised; the exchange may hold expiration until a non-erroneous revision, else last fair price
- Pre-window only; no current-conditions input
- Guidance can run cold/hot in unusual regimes (see LA diagnostic, 2026-10-04)
Weather · daily high — inputs: National Blend of Models day max (GFS MOS fallback) + station empirical guidance-error tables. This model on the research board →
Market prices are a benchmark only and never enter a PropBetEdge model. Research-stage probabilities; not advice.