Current ensemble forecasts from European meteorological models indicate a highest temperature in Paris on May 17 most likely between 15 °C and 17 °C, with clustering near 16 °C, consistent with trader positioning. A persistent blocking upper-level trough has advected cooler maritime air across northern France, suppressing afternoon warming well below the May climatological average of 19 °C at Paris-Montsouris. Model consensus shows limited diurnal recovery under mostly cloudy skies and light winds, keeping maximum temperatures in this narrow band. Météo-France observations tomorrow afternoon will resolve the market, with any unexpected clearing potentially allowing brief warming toward 17 °C while stronger cloud cover would favor 15 °C.