What the market asked
The market was a straightforward weather resolution question: what would be the highest temperature in Paris on August 13? Per the council’s own framing, settlement hinged on a narrow data source—the highest whole-degree Celsius value shown in the Weather Underground Daily Observations table for Paris-Le Bourget Airport (LFPB) on 13 August 2026. That table is driven by METAR reports, which publish integer °C, so fractional readings and other stations were out of scope. Traders were effectively pricing which integer high would appear on that specific table for that day.
What the council concluded
All four models—Gemini, Claude, GPT, and Grok—participated, with Grok as chairman. The council’s formal action was SKIP. Overall council probability sat at 52% with confidence at 55%. Their stated reasoning was explicit:
Council recommends SKIP. Confidence: 55%. Resolution is strictly the highest whole-degree Celsius value appearing in the Weather Underground Daily Observations table for Paris-Le Bourget Airport (LFPB) on 13 August 2026. That table is fed by METAR reports, which publish integer °C.
In other words, they saw a market that was technically clean but informationally awkward one day out: short-range temperature forecasts are noisy at the single-degree level, and the exact METAR-fed integer that would print on Weather Underground left little room for a high-conviction lean. Even so, when forced to rank outcomes, the council’s most likely pick was 38°C, assigned a 44% probability. That pick became the graded line under the “most_likely” basis.
What the market was pricing
The council’s internal distribution put the mode at 38°C with 44%—well below a decisive threshold, and consistent with the SKIP. A 52% headline probability paired with only 55% confidence signaled that no single bucket cleared their bar for a recommended position. Weather markets of this type often concentrate around a few adjacent integers; a 44% mode with the rest of the mass spread across nearby highs is exactly the kind of flat profile that produces a pass rather than a bet.
What actually happened
The winning outcome was 38°C—the same contract the council had ranked as most likely. Graded on that most-likely pick, the council was correct. The Brier score on the graded line was 0.3136, reflecting a probabilistic call that was directionally right but not sharply peaked. Because the official action was SKIP, there was no formal position to mark to market; the value of the exercise was in whether the ranked forecast matched reality. It did.
Takeaway
This report is a clean illustration of process over bravado. The council correctly identified resolution mechanics (LFPB / Weather Underground / integer METAR °C), correctly refused to overstate edge one day ahead on a single-degree weather print, and still put the eventual winner at the top of its distribution at 44%. Being right on the mode while choosing SKIP is not a failure of forecasting—it is a disciplined separation between “what we think is most probable” and “what we are willing to back with a position.” For weather integers near the forecast horizon, that separation is often the difference between a calibrated pass and a low-edge forced play. The grade stands: most-likely call correct, formal action SKIP, Brier 0.3136.
AI-generated analysis for informational purposes only. Not financial advice.