Recent ensemble forecasts from major models indicate Paris overnight lows on August 17 clustering tightly between 16–19 °C, with the tightest spread centered on 17–18 °C, directly underpinning the near-even market odds between those two outcomes. Clear or partly cloudy conditions expected overnight, combined with light northerly flow and typical urban heat retention, limit radiative cooling and keep minimums from dropping below the historical August baseline of roughly 15 °C. Minor divergences among model runs stem from subtle differences in predicted cloud timing and boundary-layer moisture, which can shift the exact low by 1 °C. Fresh high-resolution updates from Météo-France and ECMWF in the next 24–48 hours will likely narrow the range before the market resolves on official observations.