Springtime temperature variability in northern France keeps market odds tightly bunched near 45–50 percent across the 6–16 °C range for Paris’s May 20 low. Climatological data show average overnight minima near 10 °C at Paris-Le Bourget, yet current model guidance from Météo-France and ECMWF highlights a wide spread driven by uncertain cloud cover and boundary-layer mixing. Clear skies could allow stronger radiational cooling and push readings toward the lower buckets, while persistent low-level moisture or a mild Atlantic flow would favor values near or above 12 °C. With resolution only four days away, traders are weighting the next high-resolution model updates that will narrow the forecast envelope.