Current forecast models from agencies like Météo-France and ECMWF indicate a possible influx of cooler maritime air over northern France in the next 48 hours, driven by a weakening high-pressure system and an approaching trough, which could suppress daytime highs and lower nighttime minimums in Paris. Ensemble spreads remain wide for July 21, with guidance showing overnight lows potentially dipping to 10–14 °C under clear, radiational cooling conditions versus 15–17 °C if cloud cover or a warmer southerly flow persists. These small differences in boundary-layer moisture, wind speed, and exact frontal timing create the tight clustering of market-implied odds around the lower-to-mid teens, reflecting traders’ assessment of model consensus versus historical July variability for the Île-de-France region. Updated model runs expected in the coming hours will likely sharpen resolution criteria for the lowest temperature reading.