**Strong model consensus from multiple numerical weather prediction systems, including GFS outputs and regional forecasts, has locked in a daytime maximum of 25°C for Paris on October 4 under clearing skies and a stable anticyclone.** Afternoon temperatures climbed steadily from morning lows near 14–16°C to peak values around 25°C by mid-to-late afternoon, consistent with observed trends 3°C above seasonal normals and light northeasterly winds. This alignment of high-pressure conditions, minimal cloud cover after morning dissipation, and verified observational data explains the market's near-certain pricing on 25°C. Only an unexpected late-day measurement revision from the official Paris station or localized microclimate effects could realistically shift the recorded high, though current evidence makes such adjustments improbable.