Latest ensemble forecasts from ECMWF and GFS models point to an overnight low near 8°C in Paris on October 17, driven by northerly winds advecting cooler maritime air and clear skies promoting radiative cooling after daytime highs of 16-17°C. This autumnal pattern, consistent with seasonal climatology showing average October 17 minima of 8.5°C, explains why traders assign the highest implied probabilities to 8°C and 9°C. Minor model spread around exact timing of peak cooling and boundary-layer moisture keeps 10°C viable at lower odds, while recent runs show limited risk of dipping to 7°C or below. Updated guidance from Météo-France and NOAA will refine these thresholds ahead of market resolution.